[bad_user]

On Window XP the download for .NET 3.5 Client is just ~28Mb for machines with no framework, ~ 40 MB for .NET 4 (again, with no other version) and the web installer is only ~800 KB.

Over 80% (or even 90%) of Windows clients have some version of .NET installed, and since it's being pushed through Windows Update, some stats are reporting .NET 3.5 at more than 60%.

The Windows 7 marketshare is bigger than 10%, which means there are more Windows 7 clients out there then OS X, and I haven't seen OS X developers complaining about a lack of users willing to try out their apps.

> Web Startups and/or social applications, because of the (sql) server costs

Yes, but it really depends on your needs. PlentyOfFish / StackOverflow are doing just fine.

[BillGoates]

Details missing the point. Yes it's possible to use .NET, but Microsoft development tools aren't automatically the best choice anymore, and often even the worst choice.