PrivaCV.com includes a simple tree of skills. Right now about 80 skills. Soon about 1000. Browse the tree. Look at a market. Add a skill. Maybe you coudl do this on a relational database, but certainly harder.
Other trees are needed. Skills will be followed by trees for geographic locations and citizenship. That will allow me to create a list of all the python developers in Krakow for example.
I invite you to Register and then link to your own blog postings and