silverlight 2 (previously referred to as version 1.1) includes a version of the .net framework, implementing the same full common language runtime (clr) version as .net framework 3.0; so it can execute programs written in any .net language. (by default, however, reference assemblies compiled with the regular .net framework cannot be referenced.) unlike the clr included with .net framework version 3.5 and earlier, but like .net framework 4.0, the coreclr instance included in silverlight can be hosted with another instance of one of the desktop clrs in one single process. with this, the xaml layout markup file (codice_1 file) can be augmented by code-behind code, written in any .net language, which contains the programming logic. it can be used to programmatically manipulate both the silverlight application and the html page which hosts the silverlight control. the xaml markup, as well as the code, is compiled into cli assemblies which are then compressed using zip and stored in a codice_2 file.