Isn't that better to do in a programming environment you're more familiar with? LIke python/rails/ASP
Then you have much better tools for building unit tests and stuff too.
The performance of doing it in nginx is _much_ better, and you can't do anything complex enough for unit tests to pay off. For the SSI stuff, you have your web framework of choice produce html with SSI tags in it, cache that, and nginx just swaps out the volatile bits at the last second (even for pages in cache).
