New version of CrossKylix as been updated two weeks ago.
Even Kylix has discontinued long time ago, but it's seems still used by some of Delphi developers.
Has any one used it successfully on cross-platform development for Windows and Linux?
As Mason said, we're using CrossKylix for the Linux version of Beyond Compare, but only for release builds, which are kicked off from FinalBuilder. For that usage, it's been great. We did try doing CLX development on Windows for a while, but CLX for Windows had different bugs than CLX for Linux, so it wasn't worth it long-term.
Our actual Linux development is still done using Kylix 3 running on SuSE 10 virtual machines. We use both GDB and the Kylix debugger for debugging, though the Kylix debugger doesn't work well for backgrounds threads anymore. We dropped CLX design-time support a long time ago though, so almost all of our feature development is done in Delphi 2007 and the VCL.
I am also actively using Simon's other project, CrossFPC, for our 64-bit Windows shell extension, and it's worked great.