The (current) last update of TeX is from March 2008. The idea is that it is stable, not abandoned.

That's partly because Knuth's TeX is more the core of a piece of software than the software itself; actual distributions of TeX get much more frequent maintenance, and would bitrot without it. For example, the last commit to texlive (the TeX distribution most Linux users use) was 20 minutes ago: http://www.tug.org/svn/texlive/trunk/

You sure? I thought work was shifting to ǐTéX (ring!).

It's hard to say what active means. For example http://github.com/technoweenie/acts_as_versioned/commits/mas... hadn't had any commits in more than a year until today, but now it's up-to-date with rails 3.

Another aspect of this is whether the project is used by anyone. If a project like wget loses the maintainer, it's a big deal and we should shout on street corners about it until someone steps up. If a project is simply a piece of code that is of no use to anyone, even the original author, then we should at least rank it lowest. So maybe for the former it makes sense to add the extra field so that people can be notified instantly and someone could step up. Then again, IIRC wget did lose its mainrainer recently and someone stepped up very quickly since the project has other communication channels.