For the longest time, I've had issues where I wish there was a way to save information to a database like SQL, in some known format, and be able to query it. I don't just mean 'just use SQL', but I mean advanced features like... 'related topics', etc.
I basically wanted Graph based storage. I tried using oqgraph, since MariaDB gives access to that, and with MariaDB being binary compatible with MySQL, I could use it. But it isn't well maintained, and it tended to crash things. So I dropped that. (Read: Don't use OQGraph for SQL Graph Storage, it's a trap!)
I recently actually started work on this anew, and in doing so fixed a bug in PennMUSH's SQL handling that enabled single-return Stored Procedures -- creating Graph based functions in SQL. However, SQL isn't really made for this... with enormous tables, this'll get slow. (Read: Stored Procedures for SQL Graph Storage is the best option at the moment)
It's roughly detailed here:
http://mush-mercutio.tumblr.com/post/153345784737/pennmush-graph-framework
If I finish this, I may at some point rewrite SceneSys to use this kind of storage, and launch some basic things along with it, like a basic BBS and a basic Jobs system as a POC.
Being reflected on the MUSH and on SQL, would allow easy grabbing through websites, etc.