It is possible to contribute to the Ankur Bangla Project even if the predominant Operating System being used to participate is Windows platform variants from Microsoft, the group however suggests otherwise.
If you are working on translation work, you will need an editor that support Bangla. Traditional *nix text editors like VIM, GNU Emacs, XEmacs will not work in this case (I know, I know, it's shocking news). Currently the editors that support Bangla properly are:
This is the default text editor of GNOME 2. It supports Bangla (provided that you have have the right fonts, and setup your keyboard). It is my personal choice at present.
Kate (KDE Advanced Text Editor) is a standard text editor distributed with KDE. It should support Bangla if you have QT 3.2 or above.
Yudit is an Free text editor supporting a number of languages (including Bangla). The setup process can be a little hairy, but you will be getting a variety of keymaps with this editor. This editor is cross-platform - that means it will work on Windows too.
Lekho is yet another Free, cross-platform editor, written by a member of the Ankur Group - Kaushik Ghosh. It is easy to setup and work on, and is used by a number of translators in the team.