Internal Structure and Libraries

Kernel: written in C/C++ (appr. 150,000 lines of code); provides main and time-crucial functionality (e.g., std engine, poly operations)
Interactive user interface: ASCII based, command-driven
Help system (Manual, Tutorial): on-line, PostScript, HTML
C-like programming language: for/while loops, procedures, ...
Libraries: written in Singular programming language; augment kernel functionality
Binary network interface: can use Singular from other CAS (MuPAD, Mathematica)