rasa (hackage): A modular text editor This is only a snippet, see the project's README.  Rasa is a text editor project with a few interesting goals. For better or worse it attempts to be as modular as possible. This means that most functionality which would typically be considered to be core in other editors is implemented as extensions in Rasa. This approach comes with its own share of pros and cons, for instance:  Pros  Implementing most core functionality as extensions ensures a powerful and elegant extension interface.  Flexibility; don't like the default cursor implementation? Write your own!  Adaptability; the core of Rasa is miniscule, you can mix and match extensions to build any editor you want.  Cons  Module cross-dependencies makes the community infrastructure more fragile; We'll likely have to develop a solution to this as a community as time goes on.  Fragmentation; Not having a single implementation for a given feature means extensions that depend on a feature have to pick a specific implementation to augment. Over time data-structures and types will be standardized into Rasa's core to help alleviate this.  While highly experimental, I've found the current API to be quite expressive and adaptable; for instance I was able to implement the notion of multiple cursors using the extension API in less than a day. I hope to keep the learning curve low as development continues.  Getting Started  First clone the Github repo and try running the example-config included there. Once you get it running (see the README) then you can customize your keymap to add a few mappings you like. Then I'd check out the Building your own extensions guide. It goes in depth into everything you'd want to know!  If you have any issues (and I'm sure there'll be a few; it's a new project!) please report them here and we'll talk about it!
Keywords: executable|gpl|library|text-editor|editor|haskell|modular|rasa