GEOS provides a spatial object model and fundamental geometric functions. It implements the geometry model defined in the OpenGIS Consortium Simple Features Specification for SQL. Functions provided include:

Collection of 3D LEGO parts, 3D part primitives and two example LEGO 3D models in LDraw format. This part library is needed by 3D CAD programs such as MLCAD, LeoCAD and Konstruktor which allow one to construct LEGO models from individual LDraw parts. It is also needed by rendering software such as LDView and LdGLite or instruction creation software like LPub4 or Lic.

pg_rational implements precise fractional arithmetic for PostgreSQL. Perfect for exact arithmetic or user-specified table row ordering. Holds values as big as an integer, with matching precision in the denominator.

FLAC stands for Free Lossless Audio Codec. Grossly oversimplified, FLAC is similar to MP3, but lossless. The FLAC project consists of:

This PostgreSQL extension shows the query plans of all currently running SQL statements. Plan output format can be plain text (default), JSON, YAML, or XML.

The evaluation of a mathematical expression is a standard task required in many applications. It can be solved by either using a standard math expression parser such as muparser or by embedding a scripting language such as Lua. There are however some limitations: Although muparser is pretty fast it will only work with scalar values and although Lua is very flexible it does neither support binary operators for arrays nor complex numbers. So if you need a math expression parser with support for arrays, matrices and strings muparserx may be able to help you. It was originally based on the original muparser engine but has since evolved into a standalone project with a completely new parsing engine.