TaskLite is a CLI task manager built with Haskell and SQLite and you can check it out at tasklite.ad-si.com.
Since this is my first post announcing it here, let me give you some more background infos on why I built it:
Taskwarrior has been the gold standard for CLI task managers so far.
However, I repeatedly lost tasks due to weird bugs and syncing issues.
I also found several UI decisions inept and wanted something with a better workflow.
But probably most importantly I couldn’t see myself contributing to a C++ project.
I had been working with C++ at university and it wasn’t pleasant.
To sum it up: I finally wanted something which I could fully own
and use until the end of days.
That means:
- Does not suddenly get bought by a bigger fish and get closed down
or made unusable (looking at you Wunderlist) - Is written in a high-performance programming language,
yet gives me lot’s of guarantees about the code’s stability
and makes it easy for other developers to contribute - Free software
- With a stable, future proof, powerful, and fast backend
(currently [SQLite], but support for plain files and Git is planned)
I hope you’ll join me in my quest to build the most robust and powerful task manager in existence 
!