Not so fast ....
The Fedora Project, which is committed to FOSS, saw fit to forbid Moonlight due to legal risk:
"There are serious concerns about Moonlight, due to Microsoft and Novell's public statements around its inclusion in their "covenant". In addition to that Groklaw has posted a FAQ from Software Freedom Law Center (SFLC) on the issues with this patent "covenant". Accordingly, this technology (with, or without codecs), is considered too risky, and is not acceptable for inclusion in Fedora."