The binary will run out of the box on Mono 1.1.13.2 release. IsDaylightSavingTime issue is still there, and in addition, string encoding and decoding won't work. IronPython now uses System.Text.GetEncodings (note the plural) method, new in .NET 2, which is not yet implemented on Mono. Will report more as I find out. Seo Sanghyeon