In the past, I've bought plugins from Mixed In Key, and they have now released version 2.0 of their
Satellite plugin suite. Currently it is for free so I gave it a test spin.
What it does is basically allow you to record audio or midi data to the plugin and share it to anyone in the session. This allows you to collaborate with others.
There are a few things you can do:
1. You hear what others do and the plugin perfectly syncs its position with the position in OpenMPT as long as you don't want to do any fancy tempo changes, though I haven't tested if the plugin actually handles it. You do need to set your song to Modern tempo, speed 6 and the tempo to whatever BPM you are working in with the song.
2. You can enter notes in your pattern and in the same way you normally would control a VSTi, you can send these notes as midi data into the project where others can drag the notes in their DAW and use your notes in their project.
3. You can record your audio output of one or more instruments simultaneously into the session such that anyone else can hear exactly what it sounds like in your OpenMPT. They can drag the WAV file into their project and work with it that way.
4. If everyone only records their audio into the project, you can work on a song together without even needing to download audio back into your project. You just need to tell them to alter the volume if that is an issue.
5. There is a chat function inside that saves chat into the session.
6. OpenMPT actually does allow you to drag in midi and wav data from the session into your OpenMPT window. It will then create a new song and put the notes and or samples in that song so that you can switch to your main song and copy over the note data or import the sample back in there. Working with the audio is a bit cumbersome so its probably better to work described as step 4, but it is possible.
and last but definitely not least,
7. If you have 2 different DAW's, where OpenMPT is one of them, you can use this to easily create a song that uses both DAWs. OpenMPT for that chiptune section, and your sequencer for that ambient section, etc... Or a plugin that crashes in OpenMPT can be recorded in your other DAW and editing something is very easy now.
I'm not sure how long this will stay for free, if ever, but it works and it works quite well.
Currently I am testing it with both OpenMPT and BitWig studio, and I find that when I drag in audio or midi from the session into my project, the plugin freezes. BitWig has a really good crash protection so it allows the plugin to die but it does get the audio/midi data, and all I have to do is reload the plugin and am back in business, so that's good...
I did a test where I created a pattern with a simple sine sample in OpenMPT, recorded the midi notes, got them back in BitWig, used a different plugin with different sound and had my pattern in the song there quite easily. Something that would normally take me 15 minutes or more was now done in under 3.
Oh, and of course, this does mean that people can now easily collaborate over the internet using OpenMPT without creating a module, saving it, sending it back and forth, and not worrying about all those great plugins that you now cannot use. You can use your plugins, it stores it as wave data.
You can technically even use only OpenMPT and Satellite Sessions as standalone user to have a sequencer view in OpenMPT if that's what you want, without all the sequencer editing capabilities.
There is one thing that you have to keep in mind though, Satellite sessions does only does its magic when the sound buffer is open, so if you record something and you press stop at the end, Satellite Sessions appears to hang. Just press the upload button in the Sessions window to stop recording, hit play in your daw again, and it finalizes the recording for you.