I'm going to use Object Pascal with Lazarus IDE. Lazarus is a free cross-platform rapid application development tool: http://www.lazarus-ide.org/

And for a browser-based application I'll just be writing my own PHP.

Well, I have already decided that Tarinapaja is going to be free to use, but I'm not yet sure if it is going to be open source. So, in the live blogging session I won't be sharing pieces of source code, but it will be more like a "in-the-making-of": pictures and short updates of a day in a programmer's life =)