Hi, I am familiar with QT/gtk+ libs under linux. I've just roughly had a look at available c++ frameworks like Reason and Platinum. Does anyone have any experience working with any of them? Are they any good, should I consider learning them? I am not a big fan of frameworks though.
Keep using Qt or gtk+. They're very good, and you already know them.
I am not a fan of frameworks either, which is maybe why I haven't heard of those you mention. Having said that, check out POCO. Looks much better than Qt or gtk+ to me if you don't need GUI.
boost asio: the framework for those who are not framework fans ;-). (and this question still lacked a boost answer)
I worked on a project that had to run on multiple platforms (Linux, Windows, Windows CE). We used WxWidgets for the UI. The libraries and the tools weren't perfect. But it compiled and ran on all the platforms without any issues.
The platform is completely open source, so you have the benefits therein.
In the end, I was glad we used it as apposed to porting the UI layer multiple times.