xacc.ide is a small and fast integrated development environment (IDE) mainly targeted at .NET development. It has syntax support for 27 languages and project support for various compilers. It has support for step debugging .NET based executables. Also featured is brace matching and folding support for some languages.
xacc.ide is also opensource software (OSS). The core is released under the GNU LGPL, and the rest BSD license.
Download: xacc.ide 0.2.0.84