I've been working on a port of gitit to Yesod, which is currently called gitit2 (https://github.com/jgm/gitit2). At this point I have implemented most of the basic wiki functionality. I've really been enjoying some of Yesod's features -- especially the type-safe URLs, form support, internationalization, and widgets -- and the code is much cleaner and shorter than the original gitit code. But today I thought I'd look at performance, and I was surprised to find that gitit2 is considerably slower than the original gitit (built on happstack). For example, on one simple test page, siege recorded 9 transactions per second for gitit2, 18 for the original gitit. (This is with caching turned off, so each hit involves getting content from the git repository, parsing it, and creating an HTML wiki page. Of course most of that work is done by filestore and pandoc, which are used by both gitit and gitit2.) I'm really curious why gitit2 is so much slower, and I wonder whether I'm making some basic mistake. At this point most of the code is in one module, https://github.com/jgm/gitit2/blob/master/Network/Gitit2.hs . This defines a Yesod subsite which is wrapped by a Yesod site in the main executable, https://github.com/jgm/gitit2/blob/master/src/gitit2.hs . The benchmark I did just involved fetching the front page, so most of the handlers are irrelevant. If anyone has any useful ideas, I'd be grateful. John