ubuntu 8.04 amd64
Installation can be easy with Ubuntu/ Kubuntu 8.04 with the 64 bit version. Downloading the .deb is not available on the website directly, but go to the torrent (P2P) section and download them. Install all the packages in the unzipped file. You don't even have to remove 2.X from your machine.
Although I do concur 2.X works just as good, but for me Solver is extremely necessary as an engineering student. Definitely saved me money. Thanks Oo.o