I had one just like that back in 1999 I think was the year.
It’s a Sun Solaris computer ( UNIX )
These computer where the backbone of most Large IT departments and the internet.
That workstation must have costs about $30,000 new back in 1999/2000
They used them in large corporation to write binaries and develop software and manage the corporate computers , servers , webservers and super computers.
( Banks, Sun corp, Microsoft corp, Internet portals, tel-co’s, etc. ).
Lots of large corporation used these computers.
Sun Microsystems was one of the computer giants to come out of Silicon Valley.
( HP, Sun, SGI, IBM ).
For 5 euro’s thats a steel.
It’s a little loud however.
And BIG.
I think it came with Solaris 8.
Not much you can do with it today but learn UNIX.