| [OpenJPEG](https://www.openjpeg.org/) | OpenJPEG is an open-source JPEG 2000 codec written in C language. It has been developed in order to promote the use of JPEG 2000, a still-image compression standard from the Joint Photographic Experts Group (JPEG). Since may 2015, it is officially recognized by ISO/IEC and ITU-T as a JPEG 2000 Reference Software. |
| [PLASMA](https://icl.bitbucket.io/plasma/index.html/) | PLASMA is a software package for solving problems in dense linear algebra using multicore processors and Xeon Phi coprocessors. PLASMA provides implementations of state-of-the-art algorithms using cutting-edge task scheduling techniques. PLASMA currently offers a collection of routines for solving linear systems of equations, least squares problems, eigenvalue problems, and singular value problems. |
| [PMIx](https://pmix.org/) | Process Management for Exascale Environments PMI Exascale (PMIx) represents an attempt to provide an extended version of the PMI standard specifically designed to support clusters up to and including exascale sizes. The overall objective of the project is not to branch the existing pseudo-standard definitions - in fact, PMIx fully supports both of the existing PMI-1 and PMI-2 APIs - but rather to (a) augment and extend those APIs to eliminate some current restrictions that impact scalability, and (b) provide a reference implementation of the PMI-server that demonstrates the desired level of scalability. |
| [PNGwriter](https://github.com/pngwriter/pngwriter/) | PNGwriter is a very easy to use open source graphics library that uses PNG as its output format. The interface has been designed to be as simple and intuitive as possible. It supports plotting and reading pixels in the RGB (red, green, blue), HSV (hue, saturation, value/brightness) and CMYK (cyan, magenta, yellow, black) colour spaces, basic shapes, scaling, bilinear interpolation, full TrueType antialiased and rotated text support, bezier curves, opening existing PNG images and more. Documentation in English (and Spanish up to v0.5.4). Runs under Linux, Unix, Mac OS X and Windows. Requires libpng and optionally FreeType2 for the text support. |
| [pocl](https://portablecl.org) | Pocl is a portable open source (MIT-licensed) implementation of the OpenCL standard |
| [poppler](https://poppler.freedesktop.org) | Poppler is a PDF rendering library |
| [PROJ](https://proj.org) | Program proj is a standard Unix filter function which converts geographic longitude and latitude coordinates into cartesian coordinates |
