Infrastructure
Most of the work I’m doing right now is in the realm of infrastructure — figuring out what software to use to build Zat. The questions I’m trying to answer now include:
What language to use. Main contenders right now are PHP and Ruby. I’m leaning toward PHP mainly because there are open source versions of Digg, Del.icio.us, and even Flickr that I can use to implement similar features in Zat.
If I use PHP, what framework to use. I’m looking into CakePHP, which is receiving generally favorable reviews.
What database to use. Biggest issue is GIS support. There is a free extension to PostGreSQL called PostGIS (http://www.postgis.org/), so for a while I was pretty committed to using PostGreSQL. But I just noticed that the Reference Manual for version 5 of MySQL has some Spatial Extensions (http://dev.mysql.com/doc/refman/5.0/en/spatial-extensions.html). So now I have to do some more research to see if MySQL will be good enough. The main advantage of MySQL is speed and (to a lesser extent) ease of use.