We should learn from existing databases and projects, which might give useful experience and insight in how to organize, how to provide easy access, etc. Of course one should always, whenever possible, provide links to such other databases whenever appropriate.
- Encyclopedia of graphs: Complete list of connected simple graphs up to ten vertices, searchable by many different graph invariants
- database of L-functions, modular forms, and related objects
- Fingerprint databases for theorems (Thanks Christian!)
- The House of Graphs: Online resources and lists of graphs
- Online encyclopedia of integer sequences The paradigm of an easily accessible database in math, collecting and interlinking results, references, theorems, conjectures, … Does someone know how exactly contributions work? Can anybody edit directly? Or is there some peer review process?
- A database for number fields described here.
- Atlas of finite group representations