MultiPrefixRoute

It allows to apply multiple route prefixes using attributes in MVC5 like:

[RouteMPrefix("v1/values")]
[RouteMPrefix("v2/values")]
public class ValuesController : ApiController
{
  [Route("list")]
  [Route("get")]
  public IEnumerable<string> Get()
  {
    return new[] { "value1", "value2" };
  }
}

1. Add MultiPrefixRouteProvider.cs and RouteMPrefixAttribute.cs to your project
2. Use MultiPrefixRouteProvider when initializing attribute routing:

config.MapHttpAttributeRoutes (new MultiPrefixRouteProvider());

Detailed description is here.