pith. sign in

arxiv: 2505.05897 · v2 · pith:NPILMHGNnew · submitted 2025-05-09 · 💻 cs.CR · cs.SE

How Reliable Are FOSS Popularity Metrics? Analyzing the Effort Required for Spoofing Common Software Popularity Metrics

Pith reviewed 2026-05-22 16:26 UTC · model grok-4.3

classification 💻 cs.CR cs.SE
keywords FOSS popularity metricsmetric spoofingsybil attacknpm ecosystemopen source softwaresoftware securitymetric reliabilitythreat modeling
0
0 comments X

The pith

Many FOSS popularity metrics can be spoofed with low to moderate effort

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper investigates the reliability of quantitative metrics used to measure the popularity and impact of free and open source software projects. It decomposes these metrics into basic categories and assesses how much effort is needed to fake them from the perspective of someone controlling the project. The findings show that categories such as commit data, issue tracker activity, download numbers, repository contents, and dependency links can be altered with relatively low or moderate effort. A case study reveals a sybil attack with over 70,000 spam packages on the npm platform linked to reward systems based on these metrics. This indicates that such metrics may not be trustworthy for important decisions in software engineering.

Core claim

The analysis finds that many metric categories, especially commit data, issue-tracker activity, downloads, repository contents, and dependency relations, are manipulable with low to moderate effort, and it identifies a sybil attack comprising more than 70,000 spam packages on npm.

What carries the argument

Decomposition of combined metrics into atomic metric categories analyzed for spoofing effort under a maintainer-centered threat model

If this is right

  • Quantitative FOSS metrics should be used with much greater caution in software engineering research and practice.
  • Particular caution is needed when metrics are used for ranking, dataset construction, or any allocation process.
  • The real-world sybil attack on npm shows that manipulation is not just theoretical but has occurred at large scale.
  • Metrics that become optimization targets are especially susceptible to gaming.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If these metrics are easily spoofed, funding or award programs relying on them may need independent verification methods.
  • Future metric design could focus on signals that are harder for maintainers to fabricate, such as external usage data.
  • Platform operators might implement better detection for coordinated spam packages to protect metric integrity.

Load-bearing premise

The spoofing effort estimates assume a threat model where the attacker can act as or control the project maintainer and directly influence signals like commits or repository contents.

What would settle it

Demonstrating that a specific metric category requires high effort to spoof even when the attacker controls the maintainer, or that the identified npm sybil attack is unrelated to metric manipulation.

Figures

Figures reproduced from arXiv: 2505.05897 by Ben Swierzy, Marc Ohm, Michael Meier, Timo Pohl.

Figure 1
Figure 1. Figure 1: Spoofing effort for categories of atomic metrics Commit Data A commit is the essential unit of a version control system (VCS). Active project maintenance implies regular commits. Therefore, atomic metrics derived from commit timestamps are commonly used. However, this type of data is highly unreliable and easily spoofed. Social coding platforms display commit data unaltered. This allows maintainers to crea… view at source ↗
Figure 2
Figure 2. Figure 2: Classes of sybil packages in a sample of 100 packages These sybil attacks do not only increase the teaRank of projects but also affect other impact metrics. Past research has considered the top N ≤ 1000 most depended upon packages as benign packages for evaluating malware protec￾tion [16,38], evaluating the adoption of security best practices [24] and others [7]. We find that, at the time of writing, 532 p… view at source ↗
read the original abstract

Quantitative metrics derived from software repositories and package ecosystems are widely used to assess the impact, popularity, maintenance, and criticality of free and open source software (FOSS) projects. However, these metrics are often assumed to be reliable despite their potential susceptibility to manipulation. Prior empirical software engineering and security research deployed these in a variety of ways which assume they indeed capture project impact and popularity. Yet, the extent to which these underlying signals can be spoofed in practice, and the consequences this has for downstream uses of the metrics, has received little focused attention. To address this gap, the paper decomposes existing combined metrics into atomic metric categories, analyzes their spoofing effort under a maintainer-centered threat model, and investigates a real-world sybil attack on npm connected to an impact-based reward mechanism. The analysis finds that many metric categories, especially commit data, issue-tracker activity, downloads, repository contents, and dependency relations, are manipulable with low to moderate effort, and it identifies a sybil attack comprising more than 70,000 spam packages on npm. These results imply that quantitative FOSS metrics should be used with much greater caution in software engineering research and practice, particularly for ranking, dataset construction, and any allocation or evaluation process that turns metrics into optimization targets.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The paper decomposes existing combined FOSS popularity metrics into atomic metric categories, analyzes their spoofing effort under a maintainer-centered threat model, and investigates a real-world sybil attack on npm connected to an impact-based reward mechanism. The analysis finds that many metric categories, especially commit data, issue-tracker activity, downloads, repository contents, and dependency relations, are manipulable with low to moderate effort, and it identifies a sybil attack comprising more than 70,000 spam packages on npm. These results imply that quantitative FOSS metrics should be used with much greater caution in software engineering research and practice, particularly for ranking, dataset construction, and any allocation or evaluation process that turns metrics into optimization targets.

Significance. If the results hold, this work contributes by showing that widely used quantitative metrics for FOSS impact and popularity are susceptible to manipulation, with direct implications for empirical software engineering and security research that relies on them. The systematic decomposition of metrics into atomic categories and the grounding in a concrete real-world npm sybil attack provide a useful framework for assessing metric reliability. The paper explicitly credits the empirical observation of the large-scale attack as supporting evidence for the effort analysis.

major comments (2)
  1. [Analysis of spoofing effort for atomic metric categories] The central claim that commit data, issue-tracker activity, downloads, repository contents, and dependency relations are manipulable with low to moderate effort rests on qualitative judgments derived from the maintainer-centered threat model and metric decomposition. No section reports actual execution of the spoofing procedures (e.g., creating and pushing commits, uploading packages to trigger download counters, or fabricating dependency edges) together with wall-clock time, API-call counts, or monetary cost. Consequently the 'low to moderate' classification remains an author judgment rather than an observed quantity. This is load-bearing for the main finding.
  2. [Investigation of the npm sybil attack] The identification of a sybil attack comprising more than 70,000 spam packages on npm is presented as supporting evidence for the manipulability claims, yet the detection heuristic, confirmation that these packages were created specifically to game an impact-based reward, and any raw data or reproducibility package are not provided. This limits independent verification of the count and attribution.
minor comments (1)
  1. [Threat model] The threat model is described as maintainer-centered, but a brief explicit statement of its scope and any assumptions about attacker capabilities would improve clarity for readers.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their constructive and detailed review. The comments raise valid points about strengthening the empirical basis of our effort analysis and improving the verifiability of the npm sybil attack findings. We address each major comment below and have revised the manuscript to provide additional transparency and detail while preserving the core contributions.

read point-by-point responses
  1. Referee: [Analysis of spoofing effort for atomic metric categories] The central claim that commit data, issue-tracker activity, downloads, repository contents, and dependency relations are manipulable with low to moderate effort rests on qualitative judgments derived from the maintainer-centered threat model and metric decomposition. No section reports actual execution of the spoofing procedures (e.g., creating and pushing commits, uploading packages to trigger download counters, or fabricating dependency edges) together with wall-clock time, API-call counts, or monetary cost. Consequently the 'low to moderate' classification remains an author judgment rather than an observed quantity. This is load-bearing for the main finding.

    Authors: We acknowledge that our spoofing effort analysis is qualitative and derived from reasoning under the maintainer-centered threat model rather than from direct experimental execution. Performing actual spoofing would require creating artificial activity on production platforms, which poses ethical issues and would violate terms of service. Instead, the classification rests on a systematic decomposition of each metric into the minimal sequence of actions an adversary with maintainer access would need, cross-referenced against documented real-world incidents and platform APIs. To address the concern, we have added an appendix with expanded step-by-step procedure descriptions for each atomic category, including counts of required operations (e.g., git commands, API endpoints) and rough cost estimates drawn from public documentation and prior literature. These additions make the basis for the 'low to moderate' labels more explicit without altering the original analysis. revision: partial

  2. Referee: [Investigation of the npm sybil attack] The identification of a sybil attack comprising more than 70,000 spam packages on npm is presented as supporting evidence for the manipulability claims, yet the detection heuristic, confirmation that these packages were created specifically to game an impact-based reward, and any raw data or reproducibility package are not provided. This limits independent verification of the count and attribution.

    Authors: We agree that explicit details on the detection method and supporting artifacts would aid verification. In the revised manuscript we have expanded the section on the npm sybil attack to include the precise heuristic (name-pattern clustering, absence of functional code, temporal burst patterns, and linkage to impact-based reward programs) together with examples of confirmation evidence from package metadata and maintainer behavior. We have also added a public reproducibility repository containing the heuristic implementation, aggregate statistics, and a curated sample of 1,000 annotated packages. The full set of 70,000+ packages is too large for direct inclusion, but we now state that the complete dataset is available to researchers upon request under a data-use agreement that respects platform policies and privacy considerations. revision: yes

Circularity Check

0 steps flagged

No circularity: analysis rests on metric decomposition and external npm observation under explicit threat model

full rationale

The paper decomposes FOSS metrics into atomic categories and evaluates spoofing effort via a maintainer-centered threat model, then supports the low-to-moderate effort claim with direct observation of an existing >70k-package npm sybil attack. No equations, fitted parameters, or self-citations are used to derive the central findings; the effort classification follows from the stated assumptions rather than reducing to those assumptions by construction. The derivation chain is therefore self-contained against external benchmarks and does not exhibit any of the enumerated circularity patterns.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The paper is an empirical security analysis that rests on standard domain assumptions about metric usage in software engineering without introducing free parameters or new entities.

axioms (1)
  • domain assumption Quantitative metrics derived from software repositories and package ecosystems are widely used to assess the impact, popularity, maintenance, and criticality of FOSS projects.
    This premise is stated directly in the opening of the abstract as background for the study.

pith-pipeline@v0.9.0 · 5764 in / 1208 out tokens · 119651 ms · 2026-05-22T16:26:25.751639+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

60 extracted references · 60 canonical work pages

  1. [1]

    Arya, A., Brown, C., Pike, R., The Open Source Security Foundation: Open Source Project Criticality Score, https://github.com/ossf/criticality_score

  2. [2]

    University of Westminster Press

    Birkinbine, B.J.: Incorporating the Digital Commons: Corporate Involvement in Free and Open Source Software. University of Westminster Press. https://doi.org/ 10.16997/book39

  3. [3]

    Empirical Evidence and Further Developments of the Research

    Bonaccorsi, A., Lorenzi, D., Merito, M., Rossi, C.: Business Firms’ Engagement in Community Projects. Empirical Evidence and Further Developments of the Research. In: First International Workshop on Emerging Trends in FLOSS Research and Development (FLOSS’07: ICSE Workshops 2007). IEEE. https://doi.org/10. 1109/floss.2007.3

  4. [4]

    Brackett, S.A., Meyers, J.S., Scott, S.: O$$ security: Does more money for open source software mean better security? A proof of concept

  5. [5]

    Capiluppi, A., Stol, K.J., Boldyreff, C.: Exploring the Role of Commercial Stake- holders in Open Source Software Evolution, pp. 178–200. Springer Berlin Heidelberg. https://doi.org/10.1007/978-3-642-33442-9_12

  6. [6]

    Journal of Systems and Software84(1), 144–161 (2011)

    Capra, E., Francalanci, C., Merlo, F., Rossi-Lamastra, C.: Firms’ involvement in open source projects: A trade-off between software structural quality and popularity. Journal of Systems and Software84(1), 144–161 (2011). https://doi.org/https: //doi.org/10.1016/j.jss.2010.09.004, information Networking and Software Services 20 B. Swierzy et al

  7. [7]

    Chao, J., Tao, S., Ribbink, A.: Evaluating the evaluators: On package scores and their underlying metrics

  8. [8]

    CHAOSS: Funding Impact Measurement Working Group, https://github.com/ chaoss/wg-funding-impact

  9. [9]

    CHAOSS: Project Popularity, https://chaoss.community/kb/ metric-project-popularity/

  10. [10]

    In: Proceeding of the 2005 ACM SIGCOMM workshop on Economics of peer-to-peer systems - P2PECON ’05

    Cheng, A., Friedman, E.: Sybilproof reputation mechanisms. In: Proceeding of the 2005 ACM SIGCOMM workshop on Economics of peer-to-peer systems - P2PECON ’05. p. 128. P2PECON ’05, ACM Press. https://doi.org/10.1145/1080192.1080202

  11. [11]

    In: Proceedings of the 2017 11th Joint Meeting on Foundations of Software Engineering

    Coelho, J., Valente, M.T.: Why modern open source projects fail. In: Proceedings of the 2017 11th Joint Meeting on Foundations of Software Engineering. pp. 186–196. ESEC/FSE’17, ACM. https://doi.org/10.1145/3106237.3106246

  12. [12]

    https://doi.org/10.1016/J.INFSOF.2020.106274, https://doi.org/10.1016/j.infsof

    Coelho, J., Valente, M.T., Milen, L., Silva, L.L.: Is this GitHub project maintained? Measuring the level of maintenance activity of open-source projects122, 106274. https://doi.org/10.1016/J.INFSOF.2020.106274, https://doi.org/10.1016/j.infsof. 2020.106274

  13. [13]

    In: Proceedings of the 11th International Workshop on Cooperative and Human Aspects of Software Engineering

    Coelho, J., Valente, M.T., Silva, L.L., Hora, A.: Why we engage in FLOSS: answers from core developers. In: Proceedings of the 11th International Workshop on Cooperative and Human Aspects of Software Engineering. ICSE ’18, ACM. https: //doi.org/10.1145/3195836.3195848

  14. [14]

    Eghbal, N.: Roads and Bridges: The Unseen Labor Behind Our Digital Infrastructure, https://www.fordfoundation.org/work/learning/research-reports/ roads-and-bridges-the-unseen-labor-behind-our-digital-infrastructure/

  15. [15]

    Eldeeb, Y., Sikora, A.: How Much Are GitHub Stars Worth to You?, https:// the-guild.dev/blog/judging-open-source-by-github-stars

  16. [16]

    Traceability transformed: Generating more accurate links with pre-trained BERT models

    Ferreira, G., Jia, L., Sunshine, J., Kastner, C.: Containing malicious package updates in npm with a lightweight permission system. In: IEEE/ACM 43rd International Conference on Software Engineering. pp. 1334–1346. IEEE. https://doi.org/10. 1109/icse43902.2021.00121

  17. [17]

    Geer, D., Sieniawski, G.P.: Who Will Pay the Piper for Open Source Software Maintenance? Can We Increase Reliability as We Increase Reliance?45(2), https: //www.usenix.org/publications/login/summer2020/geer

  18. [18]

    https://doi.org/10.4018/ ijossp.2016070102

    Gerlach, J.H., Wu, C.G., Cunningham, L.F., Young, C.E.: An Exploratory Study of Conflict over Paying Debian Developers7(3), 20–38. https://doi.org/10.4018/ ijossp.2016070102

  19. [19]

    https://doi.org/10.1109/tifs.2014

    Gong, N.Z., Frank, M., Mittal, P.: Sybilbelief: A semi-supervised learning approach for structure-based sybil detection9(6), 976–987. https://doi.org/10.1109/tifs.2014. 2316975

  20. [20]

    https://doi.org/10.1109/ms.2013.95

    Gonzalez-Barahona, J.M., Izquierdo-Cortazar, D., Maffulli, S., Robles, G.: Under- standing How Companies Interact with Free Software Communities30(5), 38–45. https://doi.org/10.1109/ms.2013.95

  21. [21]

    https://doi.org/10.1109/MSP.2010.85

    Halderman, J.A.: To Strengthen Security, Change Developers’ Incentives8(2), 79–82. https://doi.org/10.1109/MSP.2010.85

  22. [22]

    In: Proceedings of the 2nd International Workshop on Software Health

    Iaffaldano, G., Steinmacher, I., Calefato, F., Gerosa, M., Lanubile, F.: Why do developers take breaks from contributing to OSS projects? a preliminary analysis. In: Proceedings of the 2nd International Workshop on Software Health. p. 9–16. SoHeal ’19, IEEE Press. https://doi.org/10.1109/SoHeal.2019.00009, https://doi. org/10.1109/SoHeal.2019.00009

  23. [23]

    Joslyn, H.: Is crypto the solution to paying open source developers?, https:// thenewstack.io/is-crypto-the-solution-to-paying-open-source-developers/ Susceptibility to Fraud of Monetary Incentive Mechanisms for FOSS 21

  24. [24]

    Kabir, M.M.A., Wang, Y., Yao, D., Meng, N.: How do developers follow security- relevantbestpracticeswhenusingnpmpackages?In:2022IEEESecureDevelopment Conference (SecDev). IEEE. https://doi.org/10.1109/secdev53368.2022.00027

  25. [25]

    https://doi.org/10.1007/s10664-015-9393-5

    Kalliamvakou, E., Gousios, G., Blincoe, K., Singer, L., German, D.M., Damian, D.: An in-depth study of the promises and perils of mining GitHub21(5), 2035–2071. https://doi.org/10.1007/s10664-015-9393-5

  26. [26]

    https: //doi.org/10.1145/3690632

    Li, X., Zhang, Y., Osborne, C., Zhou, M., Jin, Z., Liu, H.: Systematic Literature Review of Commercial Participation in Open Source Software34(2), 1–31. https: //doi.org/10.1145/3690632

  27. [27]

    In: Proceedings of the 18th ACM/IEEE International Symposium on Empirical Software Engineering and Measurement

    Linåker, J., Link, G., Lumbard, K.: Sustaining Maintenance Labor for Healthy Open Source Software Projects through Human Infrastructure: A Maintainer Perspective. In: Proceedings of the 18th ACM/IEEE International Symposium on Empirical Software Engineering and Measurement. pp. 37–48. ESEM ’24, ACM. https://doi.org/10.1145/3674805.3686667

  28. [28]

    https://doi.org/10.1109/jproc.2024.3379855

    Longtchi, T.T., Rodriguez, R.M., Al-Shawaf, L., Atyabi, A., Xu, S.: Internet-based social engineering psychology, attacks, and defenses: A survey112(3), 210–246. https://doi.org/10.1109/jproc.2024.3379855

  29. [29]

    https://doi.org/10.1109/tem.2021.3122012, http://dx.doi.org/10.1109/ TEM.2021.3122012

    Mujahid, S., Costa, D.E., Abdalkareem, R., Shihab, E., Saied, M.A., Adams, B.: Toward Using Package Centrality Trend to Identify Packages in Decline69(6), 3618–3632. https://doi.org/10.1109/tem.2021.3122012, http://dx.doi.org/10.1109/ TEM.2021.3122012

  30. [30]

    In: Proceedings of the 4th international conference on Security and privacy in communication netowrks

    Müller, W., Plötz, H., Redlich, J.P., Shiraki, T.: Sybil proof anonymous reputation management. In: Proceedings of the 4th international conference on Security and privacy in communication netowrks. pp. 1–10. Securecomm08, ACM. https://doi. org/10.1145/1460877.1460887

  31. [31]

    Open Source Initiative: The open source definition, https://opensource.org/osd

  32. [32]

    Open Source Technology Improvement Fund: Open source technology improvement fund, https://ostif.org

  33. [33]

    Open Technology Fund: Localization labfree and open source software sustainability fund, https://www.opentech.fund/funds/ free-and-open-source-software-sustainability-fund/

  34. [34]

    In: 2024 Conference on Computer-Supported Cooperative Work and Social Computing

    Osborne, C.: Open Source Software Developers’ Views on Public and Private Funding: A Case Study on scikit-learn. In: 2024 Conference on Computer-Supported Cooperative Work and Social Computing. pp. 154–161. CSCW ’24, ACM. https: //doi.org/10.1145/3678884.3681844

  35. [35]

    Democratise

    Osborne, C.: Why Companies "Democratise" Artificial Intelligence: The Case of Open Source Software Donations

  36. [36]

    Osborne, C., Sharratt, P., Foster, D., Boehm, M.: A Toolkit for Measuring the Impacts of Public Funding on Open Source Software Development

  37. [37]

    In: Proceedings of the ACM/IEEE 42nd International Conference on Software Engineering

    Overney, C., Meinicke, J., Kästner, C., Vasilescu, B.: How to not get rich: an empirical study of donations in open source. In: Proceedings of the ACM/IEEE 42nd International Conference on Software Engineering. ICSE ’20, ACM. https: //doi.org/10.1145/3377811.3380410

  38. [38]

    In: Sicherheit 2024

    Pohl, T., Ohm, M., Boes, F., Meier, M.: You can run but you can’t hide: Runtime protection against malicious package updates for node.js. In: Sicherheit 2024. pp. 231–241. Gesellschaft für Informatik e.V., Bonn (2024). https://doi.org/10.18420/ sicherheit2024_015

  39. [39]

    https: //doi.org/10.1109/mc.2010.24 22 B

    Riehle, D.: The Economic Case for Open Source Foundations43(1), 86–90. https: //doi.org/10.1109/mc.2010.24 22 B. Swierzy et al

  40. [40]

    Volunteer Work in Open Source

    Riehle, D., Riemer, P., Kolassa, C., Schmidt, M.: Paid vs. Volunteer Work in Open Source. In: 47th Hawaii International Conference on System Sciences. IEEE. https://doi.org/10.1109/hicss.2014.407

  41. [41]

    Ruohonen, J., Choudhary, G., Alami, A.: An Overview of Cyber Security Funding for Open Source Software

  42. [42]

    watchers

    Sheoran, J., Blincoe, K., Kalliamvakou, E., Damian, D., Ell, J.: Understanding “watchers” on GitHub. In: Proceedings of the 11th Working Conference on Mining Software Repositories. pp. 336–339. ICSE ’14, ACM. https://doi.org/10.1145/ 2597073.2597114

  43. [43]

    Shpota, S.: Github activity generator, https://github.com/Shpota/ github-activity-generator

  44. [44]

    Sovereign Tech Agency: Sovereign tech fund, https://www.sovereign.tech/programs/ fund

  45. [45]

    Sovereign Tech Agency: Technologist, https://www.sovereign.tech/jobs/technologist

  46. [46]

    https://doi.org/10.1002/(sici)1234-981x(199707)5:3<305::aid-euro184>3

    Strathern, M.: ‘improving ratings’: audit in the british university system5(3), 305–321. https://doi.org/10.1002/(sici)1234-981x(199707)5:3<305::aid-euro184>3. 0.co;2-4, https://doi.org/10.1002/(sici)1234-981x(199707)5:3<305::aid-euro184>3. 0.co;2-4

  47. [47]

    tea Association: Tea documentation, https://docs.tea.xyz/tea

  48. [48]

    tea Association: What is Proof of Contribution? (technical), https://docs.tea.xyz/tea/i-want-to.../learn-about-proof-of-contribution/ what-is-proof-of-contribution-technical

  49. [49]

    The Linux Foundation: Alpha-omega, https://alpha-omega.dev

  50. [50]

    Tumbleson, C.: The disappointing tea.xyz, https://connortumbleson.com/2024/02/ 26/the-disappointing-tea-xyz/

  51. [51]

    https://doi.org/10.1145/3387111

    Wang, Z., Feng, Y., Wang, Y., Jones, J.A., Redmiles, D.: Unveiling Elite Developers’ Activities in Open Source Projects29(3), 1–35. https://doi.org/10.1145/3387111

  52. [52]

    Warren, E.: Foss sustainability fund 2024: the grant proposal is declined, https: //codeberg.org/forgejo/sustainability/pulls/48

  53. [53]

    https://doi.org/10.1111/j.1467-9310.2006

    West,J.,Gallagher,S.:Challengesofopeninnovation:theparadoxoffirminvestment in open-source software36(3), 319–331. https://doi.org/10.1111/j.1467-9310.2006. 00436.x

  54. [54]

    In: Proceedings of the 14th International Workshop on Principles of Software Evolution

    Yamashita, K., McIntosh, S., Kamei, Y., Hassan, A.E., Ubayashi, N.: Revisiting the applicability of the pareto principle to core development teams in open source software projects. In: Proceedings of the 14th International Workshop on Principles of Software Evolution. ESEC/FSE’15, ACM. https://doi.org/10.1145/2804360. 2804366

  55. [55]

    https://doi.org/10.1109/access.2024.3403197

    Zaoui, M., Yousra, B., Yassine, S., Yassine, M., Karim, O.: A comprehensive taxonomy of social engineering attacks and defense mechanisms: Toward effective mitigation strategies12, 72224–72241. https://doi.org/10.1109/access.2024.3403197

  56. [56]

    In: CHI Conference on Human Factors in Computing Systems

    Zhang, X., Wang, T., Yu, Y., Zeng, Q., Li, Z., Wang, H.: Who, what, why and how? towards the monetary incentive in crowd collaboration: A case study of github’s sponsor mechanism. In: CHI Conference on Human Factors in Computing Systems. pp. 1–18. CHI ’22, ACM. https://doi.org/10.1145/3491102.3501822

  57. [57]

    https://doi.org/10.1145/3510849

    Zhang, Y., Liu, H., Tan, X., Zhou, M., Jin, Z., Zhu, J.: Turnover of Companies in OpenStack: Prevalence and Rationale31(4), 1–24. https://doi.org/10.1145/3510849

  58. [58]

    In: Proceedings of the IEEE/ACM 46th International Conference on Software Engineering

    Zhang, Y., Qin, M., Stol, K.J., Zhou, M., Liu, H.: How Are Paid and Volunteer Open Source Developers Different? A Study of the Rust Project. In: Proceedings of the IEEE/ACM 46th International Conference on Software Engineering. pp. 1–13. ICSE ’24, ACM. https://doi.org/10.1145/3597503.3639197 Susceptibility to Fraud of Monetary Incentive Mechanisms for FOSS 23

  59. [59]

    In: Proceedings of the 30th ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering

    Zhang, Y., Stol, K.J., Liu, H., Zhou, M.: Corporate dominance in open source ecosystems: a case study of OpenStack. In: Proceedings of the 30th ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering. pp. 1048–1060. ESEC/FSE ’22, ACM. https://doi.org/10. 1145/3540250.3549117

  60. [60]

    https://doi.org/10.1007/s10664-021-10060-y

    Zhou, J., Wang, S., Kamei, Y., Hassan, A.E., Ubayashi, N.: Studying donations and their expenses in open source projects: a case study of GitHub projects collecting do- nations through open collectives27(1). https://doi.org/10.1007/s10664-021-10060-y