Any way to keep two versions of Xorg?

[Thomas Mueller]

Is there any way to keep two versions of Xorg-server, using no more than one at a time?

Reason is the newer but unstable version with KMS, permitting full use of the newer Intel graphics chips.

I switched to the new version but then couldn't run X at all, immediately crashing the system and requiring Reset button.

I had a hard time but finally succeeded switching back, but would like if possible to see if anything can be done to make the newer Xorg work but without leaving myself entirely without a usable X.  Sort of like China and Hong Kong: one country, two systems.

Portupgrading/portmastering from the older Xorg to the newer Xorg only to have to switch back is too much trouble!  Would I have to have a second installation, on a separate partition, with FreeBSD current (HEAD), to try the new Xorg, while keeping the older Xorg on 9-STABLE?  I have enough hard drive space and use GPT, so no problem running short of partitions.

Tom