"As far as I am concerned, the only case where it is
acceptable to have multiple versions of the same software is when
the use of that software is significantly different and
disconnected from other uses. For example, if you want to make a
version with a custom interface for netbooks in addition to a
desktop edition, that makes sense, because you use a netbook in a
fundamentally different way than you use a normal computer.
Likewise, a server version of your software is also very logical,
since you use a server in a completely different way than you use a
desktop or a netbook."