How to find out what tools and approaches startups are using?

Is there something like TechCrunch CrunchBase but which provides more detailed info into the toolsets various startups use and the approaches they take? CrunchBase provides basic info on this and only by reading the blogs of various startups can I find out if they used debian/CentOS/other with mongrel/lighttp/other running RoR/Django/php/other and mysql/postgresql/other on AWS/some-host/other. I would be interested to see what people start with and how/if the tools and approaches used change over time as the startup and tools evolve. Much can be determined just by seeing the change histories, ideally gauging it with other events such as changes in hosting or user numbers or startup state. This would greatly aid me and others in various decisions. I have already started this process and will put my findings into a wiki shortly. I am in the middle of building a timeline tool to allow visual comparison and analysis. Comments, feedback, insights much appreciated.