Neil

Well, remember that dotNET includes ILDASM whose purpose is to take MSIL distributables and decompile them!

Meanwhile tools like Reflector do an even better job of reverse-engineering MSIL source.

As you'll know, dotNET now comes with an obfuscator that can break ILDASM. This obfuscator cannot totally prevent decompilation but does significantly reduce the value of the decompiled source to the point where huge effort is required to interpret it and full recreation of your work is unlikely to be obtained because of the inhumane method overloading.

IMHO it isn't so much "decompilation" that matters, but protection of precious IP against reverse engineering and theft. In such a case, physical/OS security is just as important- if you can prevent Mr Hacker getting his hands on the exe, he/she can't crack it. E.g. one of our apps retains the app on a server under our control, with customers submitting messages via HTTP across a VPN and receiving results. I think this will become a lot more common- installing *anything* at a customer exposes its content to risk if you use any of these newer languages- or even if you write in assembly.

Regards

j.R