A few years ago SAP released its MaxDB under GPL. Newer versions are not open source anymore, but you can still download the open source versions of MaxDB from their FTP server. On all other places in the WEB the software seems to be gone.
Update 9/6/18:
The SAP ftp server seems to be gone too.
Here is a mirror with maxdb 7.6.
Thank you thank you thank you! It was so difficult to find where I can get the old files!
I am having trouble undertsanding where the x_server executable is. It doesn't seem to be in either of the linux 64bit maxdb-all-linux-64bit-x86_64 files.
I am wondering if anyone knows why.