Is the MS Project 2013 Plugin backwards compatible with MS Project 2003-2010?

Hi,

I needs to develop a plugin for MS Project 2013. I want to know the MS Project 2013 plugin is backward compatible with MS Project 2003-2010. 

I am going to develop VSTO style add in for MS Project 2013 using VS2012. Can it support older version MS Projects 2003, 2007 and 2010? or should I develop COM Add-in usingIDTExtensibility2 for supporting older versions?

And also I want to know that is it possible to develop VSTO style addin for MS Project 2013 using Visual Studio 2010 and IDTExtensibility2 COM Add-in for MS Project 2013 using Visual Studio 2010.

I needs to develop a plugin for MS Project 2013. I want to know the MS Project 2013 plugin is backward compatible with MS Project 2003-2010. 

I am going to develop VSTO style add in for MS Project 2013 using VS2012. Can it support older version MS Projects 2003, 2007 and 2010? or should I develop COM Add-in using IDTExtensibility2 for supporting older versions?

And also I want to know that is it possible to develop VSTO style addin for MS Project 2013 using Visual Studio 2010 and  IDTExtensibility2 COM Add-in for MS Project 2013 using Visual Studio 2010.

I already have addin for MS Project 2003. Will it support MS project 2013?

Thanks in advance.