Linux and similar free software have proliferating different versions, because everybody can go into the source code, and everybody does.

Judge as of March 1999. TRUE: by 1999 Linux and similar open-source software existed in many differing versions or distributions (for example Red Hat, Debian, Slackware, SuSE, and different kernel patch sets or forks), because the open source code let many parties modify and redistribute it, and many did. MOSTLY TRUE: multiple versions or distributions existed and modification was common, but 'everybody' modifying the source code overstates it, or the variants shared a largely common core rather than truly diverging. MIXED: distributions existed but were mainly packaging differences with little real fragmentation, so the 'proliferation' point is only half right. MOSTLY FALSE: only a few versions existed and source modification was limited to a small core group, so the claim greatly overstates. FALSE: in 1999 Linux existed in essentially one version, with no meaningful proliferation of variants.

Set before the research began.

1. E1 Linux for dummies? Salon · 11 May 1999

   “The various Linux distributions continue to morph into distinctly different identities.”

2. E2 Linux for dummies? Salon · 11 May 1999

   “There are enormous differences in how the distributions are configured”

3. E3 Linux for dummies? Salon · 11 May 1999

   “Caldera’s version of Linux, designed to work with KDE, is different from a Red Hat system running KDE.”

4. E4 Linux for dummies? Salon · 11 May 1999

   “all the distributions use the same basic kernel at the operating system’s heart, and the fact that all operating-system code is open-source and available for inspection means that it is much easier to solve incompatibility issues.”

A Salon article from May 1999, independent of the subject, reports that Linux distributions were taking on "distinctly different identities" (E1) and differed enormously in configuration (E2). It also says Caldera's version differed from Red Hat's (E3). The same article notes that all distributions used the same basic kernel and that the open code made incompatibilities easier to fix (E4). This fits the criteria's mostly-true case: several variants existed, but they shared a largely common core, and the evidence does not support the claim that "everybody" modified the source.