Paid, obviously. But at least has some decent drafts it seems.
Versions:
- Verilog-95. IEEE 1364-1995..
- Verilog 2001. IEEE 1364-2001.
- Verilog 2005. IEEE 1364-2005.
- SystemVerilog. IEEE 1800-2012. Was a third party superset of 2005, and it was later merge / accepted into IEEE.
Where to get free versions: http://stackoverflow.com/questions/16399064/how-do-i-get-the-verilog-language-standard