The registry itself, is a database, by an application, I assume something like a registry cleaner maybe?, and for web, I assume for manual reference?.
It's tricky, many people use registry cleaners for ease and because of a usually easily understood GUI, although, in general the advice is not to mess about with the registry at all.
If you're confident enough, and knowledgeable enough, to be able to manually clean the registry, why would you think of using an app.?
If you're going through the Software keys, why would you need any web reference, surely you know already, which software you have/require?
The only possible reason I can think of for using any web referece would be for identifyiny CLSID keys, for which Google is good enough, why would you want to interfere with SAM, or control set, no application does, and unless you fancy re-building your OS from scratch, when you make a mistake, why would you want to mess about with them either?