Whichever one you have to Google the least is the best solution. Proprietary-or-not at the web server level is not even worth thinking about - the only part of MS you have to be cautious about is if you accidentally an SQL Server farm and that's easy to avoid in this day and age.
If you go with .NET then make sure you check out BizSpark, you can get free Visual Studio, Windows and everything else they make for 3 years:
Comments
Whichever one you have to Google the least is the best solution. Proprietary-or-not at the web server level is not even worth thinking about - the only part of MS you have to be cautious about is if you accidentally an SQL Server farm and that's easy to avoid in this day and age.
If you go with .NET then make sure you check out BizSpark, you can get free Visual Studio, Windows and everything else they make for 3 years:
http://www.microsoft.com/bizspark