I doubt there are many readers who know about ESTIC. It is a multi-platform (Dos, Windows, Linux, *BSD, OS/2) configuration software for some ISDN PBX systems (ISTEC 1003/1008) that used to be common in the early to mid 90's in Germany.
The original vendor of the PBX went out of business long time ago, and the author of the ESTIC tool even removed his ESTIC homepage in 1997.
Anyway, I still have some of the old ISTEC boxes in use, even at friends places. It turned out that we needed to reconfigure one of these old boxes, so I took the source code (yes, it's open source) and made it compile with recent gcc. Jeez, I never liked C++...
So if anybody is interested in the patch to compile estic 1.60 with gcc-3.3.4 on Linux: it's located at ftp://ftp.gnumonks.org/pub/patches/es160src-linux-gcc3.3.4.patch.