nostalgic phenomenon (if you liked oberon ;-P)
I used Oberon back on the old SparcStation IPX, I think it was in ’93 or so. I learned a lot of OO techniques off it. It was the first language that showed me that C/C++ style pointer arithmetic was not a requirement for an effective systems (and application) programming language. Oberon and Oberon-2 were fairly influential (if little used) languages that have influenced a number of successors including most recently Golang.
The Oberon system was published in its entirety in a very nice book, still available, which includes descriptions of the compiler and editor.
Kudos to the developers of this app for bringing back a bit of history.
KingPurply about Oberon Core