The projects appear to be for web-based infrastructure, websites, or mobile apps, with no source code for Microsoft desktop software released, including Windows, Windows Server, and Microsoft Office.

Security Affairs shared a screenshot, shown below, of the uncompressed 7zip archive that contains the 37GB of source code belonging to hundreds of Microsoft projects. Source: Security Affairs.

Code commonly flows downstream, from an open-source project into an organization’s own products. Upstreaming is the process of reversing that flow—contributing code back to an open-source project.

Pro Security Jaw-dropping security flaws found in open source code could allow hackers to spirit away entire projects - here's what devs need to know News By Efosa Udinmwen published June 18, 2025 ...

2. Software as a Service An open source project that has generated plenty of demand can choose to offer a Software as a Service (SaaS) business model.

More than half (52%) of critical open source projects contain code written in a memory-unsafe language, according to a new analysis by the Cybersecurity and Infrastructure Security Agency (CISA) in ...

Now DARPA, the US military’s research arm, wants to understand the collision of code and community that makes these open-source projects work, in order to better understand the risks they face ...