1. Typed subapplications: similar to CFBs typed subapplications group a FB network. The main difference is that subapplication content can be mapped to different devices (currently not yet possible in 4diac IDE).
   
2. Untyped subapplications: this is a feature which will be added in the upcoming 3rd edition of IEC 61499. Untyped subapplications can be created directly in apps and subapps without the need to create a type first.
   

Great to hear that. I also see subapps as a key feature for improved application design. Therefore we are currently heavily improving subapp support. If you would like to see earlier what we are doing you can also point your 4diac IDE update to our development update site. We have three different:

1. Nightly: https://download.eclipse.org/4diac/updates/nightly
Built every day at midnight Ottawa time, if there is something new in the development branch

2. Milestone: https://download.eclipse.org/4diac/updates/milestone
Intermediate milestone build, triggered roughly every one to two weeks

3. Release Candidate: https://download.eclipse.org/4diac/updates/milestone
Build roughly every 4 weeks containing the current state of the next release branch ( a bit more stable)

I'm not advertising these sites to much as they all provide you with alpha and beta version of the next 4diac IDE release. But if you would like to get a sneak preview on the next features or bug fixes you could give them a try.