Posted on behalf of RMS:

Many of the postings here talk about my "support for open source." For instance, the first posting mentions my "insistence that all software should be open source." That is a misunderstanding, because what I advocate is the free software movement -- a different idea based on different values.

See https://gnu.org/philosophy/open-source-misses-the-point.html for an explanation of what free software and open source have in common, and where they differ. See fsf.org/tedx for a quick intro to the free software idea -- if you only know the open source idea, it may surprise you.