Forum OpenACS Q&A: Response to Windows, AOLServer, and OACS
John's already done alot of the hardwork in porting to SQL Server. he's at least half of the way there. So supporting SQL Server is much easier and much closer on the horizon than either mod_nsd for Apache2 or building Windows functionality back into AOLserver.
I feel pretty confident that if you went into a window's shop and said that they could use SQL Server they would be much more comfortable about considering running AOLserver in cygwin. In cygwin, AFAIK, the sysadmin still needs to have some Unix experience. I don't see much gain if the admins are using Windows but still have to use Unix emulations to run the apps.
Even if SQL Server is 5 years behind, people in the Windows world don't know or don't care. They want to be able to use the administrative tools and buzzwords that they are comfortable with. SQL Server probably has all sorts of whiz bang apps that these admins would be pissed if they didn't have.
Don, as far as maintaining another RDBMS I agree it will add another degree of hassle. But even maintaining two DBs will be a hassle if we don't build tools to lessen the burden of developing for various systems. Tom Jackson and John Sequiera's tools that automagically deploy or convert code for multiple DBs are important steps.