It still is though it's recently called FinTS. Most german banks implement it and it's read/write usually.
Every bank has some specialities (even sometimes some bank branches have specialities) so it's usually not _that_ easy to implement if you want support for all banks.
"All" banks in Germany are run by less than 10 data centers. The second biggest, Fiducia, operates about 600 banks. This is one API for 600 banks.
For the API - almost all business accounts support HBCI or EBICS. For example my tax accountant and tax software have full access to my business account.
