I was wondering about how frequently the kernel in the Plan 9 iso is recompiled. (Probably wrong grammar there. My apologies.)
The CD image is recreated whenever there are changes, usually every night. The 9pcflop and 9pccd kernels (the ones used to boot the install CD) are updated nightly too. The 9pcf kernel (the one installed and used for regular booting) is not updated as frequently. Russ
