Are you interested in working on a text editor? If so, I have an idea I plan on implementing myself for fun: a clone of HeyNote with some added functionality. HeyNote is a simple buffer that consists of blocks. It's useful when you just want to note a simple block of text (an SQL query, log output, test data) but you are not interested in structuring it. What HeyNote lacks is the ability to add title and tags to blocks. It's not an alternative to other note taking applications. It is just a buffer with unrelated blocks in it.