ASP Classic Compiler is now open source

After weeks of preparation, I have opened the source code for my ASP Classic Compiler under the Apache 2.0 license. I conceived the project in 2009 when I joint a company that had a large amount of ASP Classic code. The economy was very slow at the time so I had some energy left to start the work as a hobby. As the economy recovers, I was getting busier with my day-time job. We converted most of our ASP Classic code to .net so that this project would no longer be useful for my own use. However, I truly hope that this project will be useful to those who can still use it.

The project had gone a long way to implement most features in the VBScript 3.0 standard. It is capable of running the Microsoft FMStock 1.0 end to end sample application. I chose VBScript 3.0 in my initial implementation because VBScript 3.0 is a language with dynamic type and static membership. ASP Classic Compiler is faster than most of the Javascript implementations and is about 3 times faster than the IIS ASP interpreter in limited benchmark test. Many users have requested VBScript 5.0 features such as Class, Execute and Eval. VBScript 5.0 has dynamic membership like Javascript. To avoid the performance hit, I have done some research to optimize the performance for the mostly static scenariou, but have yet to find time to implement it.

For this project to be successful, I truly need community involvement. In the next few days, I will outline what need to be done. I will stay as the project lead until we find a suitable new leader.


  • Hi,
    Just a small question. Do you support asp with JScript ?
    Because we migrated a lot of application from asp to with JS code. So I raise this question.

  • It does no support JScript. However, it is possible to host one of the existing Javascript .net implementations, such as IronJS or JInt.

  • Bryan,

    Yes, it is possible. Look into the unit testing project in ASP Classic Compiler. You can use it as an example how to host the VBScript.NET outside of You will also see how I feed host objects to the script.


  • Hi, There are no downloads on the copeplex page. Where do we get this program?

  • Dave, go to source code to download the latest source code.

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