When developing a project with VB6, we created a module and put every project-wide constant in it.
Now, using C#, how can we manage project-wide constants?
Put them in a static class.
If you need this class referenced in many solutions create a project in which you put this class. Add references to it.
You may also use a Singleton pattern. That is a class a class of which only one instance exists. The class itself is not static but you have only one instance of that class and you may provide it through a static property (MyConfig.Configuration in the sample).
public class MyConfig
{
static MyConfig configuration = new MyConfig();
public static MyConfig Configuration { return configuration; }
readonly string version;
public string Version { get { return version; } }
MyConfig() { version = "0.1"; }
}