Version 9.0

Intel recommend to use the latest supported Quartus version for the device family used. Quartus v9.0 is definitely been discontinued.

If you do not find the desired Quartus version in the Intel Software Download Center, it is usually indicate that the software has been discontinued and you cant download it anymore.

Intel Software Download Center:

https://www.intel.com/content/www/us/en/collections/products/fpga/software/downloads.html?s=Newest

Use the left-hand filter pane to refine the search results. Example click the desired device family to get the list of the latest supported Quartus version.