Hi! I'm software developer and now I work mostly with highly loaded systems. Recently I learned about Umbraco and I would like to sort out some issues, since I have project and I would like to test (or transfer it completely) on this platform. Since there is no strict and uniform documentation (although there are a lot of sources), in order to find a solution with an obvious problem, I would like to know: - as far as the platform is expandable - flexible API or not, for writing its own modules, complementary functionality, data types, macros, etc.; - what other databases are supported, except for those I have already learned about (SQL Server, MySQL, VistaDB).