Somebody should update the website on Sourceforge (http://simutrans.sourceforge.net/). It says 0.99.17 is the latest stable release.
Well, not all releases are considered stable. Before 99.17.1 actually 88.10.5 was the last one officially called "stable"... 100.0 certainly isn't and prissi didn't want to call 101.0 stable either - so there's nothing to change, is there?
a small error in the Simutrans Maps reference: heighmaps -> heightmaps
Anyway, a new site, better, a site revamp is on progress, right now. Wait.
EDIT:
Fixed in new site.
Topic was split. The discussion about new stable release candidate now happens here:
http://forum.simutrans.com/index.php?topic=1287.0