Quote from PQ
GtkRadiant 1.2.12 is now available for download, as well as the first of the 1.3 builds for Linux. GtkRadiant 1.2.12 includes some tweaking, improved support for SoF2, JKII, and STV:EF, as well as the new v2.3.28 of Q3Map2. Read the latest news from TTimo, find out more about the GtkRadiant 1.3 Linux release, and pick up the new files on the Radiant site.
So go get it! Now!