An extendible Motorola 6800 emulator and IDE. You can implement and add additional devices, configure the address space by using definition files, write and assemble code, debug your program using the debugger, export and import S-Record files and more.
Brainfuck Center is an IDE and compiler for your Brainfuck scripts. It includes a full debugger with step-by-step debugging and much more. MDI window!
An integrated development environment for the open sourcetext game language called AGT. I am writing the IDE in C#.
Carving Debugger is a debugging tool which support win32 user level (ring 3) debugging.