The modules in this site indeed are less than 10kSLOC (about 9070 SLOC), but we have to consider that in Oberon - in contrast to C - usually many statements are

The modules in this site indeed are less than 10kSLOC (about 9070 SLOC), but we have to consider that in Oberon - in contrast to C - usually many statements are written on the same line; there seem to be at least two statements in each line; three to four statements seem to be common. So you can multiply the SLOC by at least two when comparing with a common C program. And I neither would call it an IDE, since it lacks most features which we associate with IDEs since the late nineties (e.g. no source-level debugger, no syntax coloring or cross-referencing, etc.).