To exchange Merlin project files with MS Project users of contemporary versions, choose File > Export > MS Project > XML
MS Project 2007
For the MS Project users to open the thus exported XML MS Project files,
Today we’ve released a new free update. The 2.8.5 update brings various improvements and more stability. It is recommended for all Merlin and Merlin Server users.
Resolved Issues in Merlin
Merlin’s compatibility to Windows and mainly MS Project is very important not only to us but also to our users. Â What if you were practicing project management on windows and have lots of existing projects which you would like to use now on your Mac? Or what it you have to forward a project to a Windows user needing to edit it further in MS Project? That’s fine. With Merlin you can handle both situations just as well.
Merlin opens MS Project .mpx, .mpp, .xml file formats and exports in .xml, .mpx.
Are you wandering which file format should be preferred? The answer is easy:
We -and even Microsoft- recommend to use the XML format as it is open and reliable.
Only when trying to exchange files with MS Project users of older versions than MS Project 2000, you would need to choose a legacy format like mpx.
Simple, isn’t?
If you have MS Projects containing user defined columns and need to edit them in Merlin, simply save those files in the MS Project XML exchange format. Open the XML file later on in Merlin, click any activity in your project and check the ‘User Defined Fields’ tab. You will find them all listed there displaying their contents.
Please note:
MS Project will not save the custom titles into the XML file, so Merlin displays their column identifier.
Tip:
Isn’t great?  Not only seamless import of MS Project  files but also to such a deep extent.  Merlin never ceases to amaze me 🙂