Neovim is a project that seeks to aggressively refactor vim in order to:

• Simplify maintenance
• Split the work between multiple developers
• Enable the implementation of new/modern user interfaces without any modifications to the core source
• Improve extensibility with a new plugin architecture

For lots more details, see the wiki!

• Source tree was cleaned up, leaving only files necessary for compilation/testing of the core
• Source files were processed with unifdef to remove tons of FEAT_* macros
• Files were processed with uncrustify to normalize source code formatting
• The autotools build system was replaced by CMake

• Porting all IO to libuv
• Lots of refactoring
• A VimL -> Lua transpiler

There is a formula for OSX/homebrew, a PKGBUILD for Arch Linux, and detailed instructions for building on other OSes.

See the wiki!

Join the community on IRC in #neovim on Freenode or the mailing list

...would be awesome! See the wiki for more details.

Vim itself is distributed under the terms of the Vim License. See vim-license.txt for details.

Vim also includes a message along the following lines:

Vim is Charityware.  You can use and copy it as much as you like, but you are
encouraged to make a donation for needy children in Uganda.  Please see the
kcc section of the vim docs or visit the ICCF web site, available at these URLs:

        http://iccf-holland.org/
        http://www.vim.org/iccf/
        http://www.iccf.nl/

You can also sponsor the development of Vim.  Vim sponsors can vote for
features.  The money goes to Uganda anyway.