tSIP softphone is built using Turbo C++ Explorer. This IDE is the free (even for commercial usage but with slightly limited functionality) version of C++ Builder 2006 or BDS 2006 (Borland Developer Studio). It has it strengths and weaknesses but the main problem may be it is no longer available - it was shut down and replaced with paid versions.

Why C++ Builder?

While I haven't tested it personally building tSIP with newer version of C++ Builder (in particular version 2009 and up) may cause some troubles due to VCL transition to Unicode.

Turbo C++ Explorer works best with Windows XP. For Windows 7 start using included with sources run_bds.bat (this is deleting EditorLineEnds.ttr file each time, otherwise IDE would not start correctly) and run as administrator.

TC++ has a number of bugs related to unnecessary rebuilding of multiple projects in group and opposite - not including changes in top level project if library project changed. To mitigate these problems multiple project group files are provided - for initial build use tSIP.bdsgroup (with both Debug and Release targets), if only top level (GUI) has to be changed use tSIP_exe.bdsgroup.

Other, very annoying kind of bugs is incorrect code generation - sometimes just randomly, without obvious cause (IDE restart or whole project rebuild helps), sometimes related to inline functions (that forced me to change some re function to non-inline) when instead of running code from inline function at some point execution just jumps to some random function.

Random IDE crashes are also not uncommon.
TC++ crash
I think many of these problems are fixed in newer version, although C++ Builder is little too expensive for private/non-commercial use. At the moment (2016.11) C++ Builder 10.1 Starter is given out for free (similar to TC++ Explorer few years ago), but this version has quite limited debugging capabilities (no "Local Variables", no "Debug/Inspect") which is very annoying when working with anything but small project. On top of that it cannot import TC++ project files making transition time consuming.

Back to tSIP.

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