A complete, portable Virtual Boy development environment for Windows. Only download, unzip and start working, no installation, no hassle. It comes in the form of an editor (Notepad++, IntelliJ IDEA in the Pro version) with buttons for compiling, running on an emulator or flashing to a FlashBoy. It contains a lot of example code which can be used as a starting base for new projects.
VBDE has since been superceded by VUEngine Studio and is now considered dead.