The Altera Quartus tool series have version 8.x for all the versions
released in 2008; they've followed that scheme since 2002. I think it
took until 2005 until anyone outside Altera noticed, but it was
reasonably clean. Presumably it will be 10.x in 2010.
Clearly, the 2. prefix has long outlived its usefulness as far as Linux
is concerned, and probably the 6 as well. I personally don't think
two-digit numbers are a big problem, although three-digit numbers *are*,
which is probably why a lot of software has x.xx format version identifiers.
-hpa
--