The author seems to be focusing his argument primarily on productivity and tooling. In that regard, I agree that C# and all the surrounding OSS has surpassed va

The author seems to be focusing his argument primarily on productivity and tooling. In that regard, I agree that C# and all the surrounding OSS has surpassed vanilla Java and is starting to catch up to Rails. However, he neglects to mention anything about deployment, hosting, data storage, and long term infrastructure costs associated with being on Windows and .NET. These are real problems that startups have to weigh along side productivity when choosing their stack. While Mono is certainly an option, the recent shaky history surrounding its corporate sponsorship makes it a riskier choice. Also you lose most of the tooling advantages if you use Mono on Linux instead of .NET on Windows.