Thanks for trying out our product. We hope you enjoy working with it.
Sitefinity supports two types of modules - intra-site and pluggable. All modules that come installed with Sitefinity are pluggable modules, except for the sample Jobs module coming with a sample JobsIntraSite. Pluggable modules are compiled assemblies which can be deployed to multiple Sitefinity projects. Intra-site modules, on the other hand, are specific to the project they reside in. They cannot be shared between projects and are not compiled. Rather, they are source files in the App_Code folder of your project. Refer to our Developer Manual for more information on types of modules and their creation.
Depending on your needs, you can create either an intra-site or a pluggable module. In both cases, you can use VB.NET instead of C#. With pluggable modules, your assembly is compiled so it doesn't matter how you wrote it, it only needs to conform to all requirements for Sitefinity modules. However, with pluggable modules you have to use custom controls (as opposed to user controls or .ascx files).
If you want to use user controls, you can go for an intra-site module. Look at the sample Jobs module coming with Sitefinity for details. Although the Jobs module is written in C#, you can do it in VB with no problems.
I want to clarify that the ASCX files you have cited are NOT user controls, they are just templates used to specify the markup of custom controls used in our modules. This is done with the purpose of separating the presentation from the implementation. They are loaded dynamically from code and can be changed if you want a different layout of your module controls. However, they are not controls by themselves.
In short, you CAN use VB, just in the same way as C#. If you want to use User Controls, create an intra-site module, otherwise, a pluggable one. Do not hesitate to ask if you have any other questions about Sitefinity, we would be glad to help. Also, check out our online forums, User manual and Developer manual.
the Telerik team