**C: C programming language comments translator state machine**[information / source]*opensource*- Translates C++ comments to C comments. A (simple, somewhat optimized) state machine takes care of the translation. The translator can be seen as a simple language lexer for C-oid programming languages (C/C++/Java/...) .
**C: Figure construction patterns**[information / source / source / source]*opensource*- Figure construction patterns for figures constructed from squares [polyominoes].
**C: Rich text format normalization tool**[information / source]*opensource*- Normalizes RTF documents. Normalized formats are useable with version control tools and readable as raw data (i.e. without wysiwyg application).
**C: Sparse file converter**[information / source]*opensource*- Translates (sparse) data (back) into sparse files. Useful for data that got eventually expanded while copied, moved or restored.
**C++: VRML glass constructor**[information / source]*opensource*- Allows to design drinking glasses as virtual reality modeling language representations.
**Java: Big rational numbers**[information / source]*opensource*- Dynamically sized big rational numbers for Java. Big rational numbers allow exact calculations with the operations add/subtract/multiply/divide. May be of help with money data types.
**Java: Big rational numbers calculator**[source]*opensource*- Calculator to illustrate the use of BigRationals, including NaN handling and persistence, as well as an adapter for Java math functions (reflective, as illustration for custom plugins).
**Java, PostScript: Graphics Turtle**[information / source / source]*opensource*- The Graphics Turtle, known from the Logo programming language, is a cursor that has a position (X and Y coordinates), a heading and a pen up/down state. Procedures as forward, left, etc are used as drawing idioms.
**Lisp, Mathematica: Blackjack game probabilities**[information / source / source]*opensource*- Basic strategy (uncounted, 'infinite' deck) Blackjack game probabilities. The useful hit/stand strategy tables are calculated based on these probabilities.
**Mathematica: Graphics to VRML converter**[information / source]*opensource*- Provides a set of functions to convert Mathematica 3D graphics objects to virtual reality modeling language (VRML, version 1.0) documents.
**Palm/RPN: regressions**[information / source]*opensource*- Linear, logarithmic, exponential and power two variable regressions for Palm's RPN calculator.

**puzzles, riddles**

**C++: c't's 3d packing puzzle**[information / source]*opensource*- Calculates three-dimensional packings of 12 puzzle pieces into a cuboid of appropriate size. The pieces consist of four to six cubes of the same size, interconnected at the cubes' sides.
**Java: a visual riddle**[information / source]*opensource*- Lets the user gradually increase visual effects, to help understanding/solving the riddle.