| [libpng](http://www.libpng.org/pub/png/libpng.html) | libpng is the official PNG reference library |
| [libpthread-stubs](http://xcb.freedesktop.org/) | The X protocol C-language Binding (XCB) is a replacement for Xlib featuring a small footprint, latency hiding, direct access to the protocol, improved threading support, and extensibility. |
| [libreadline](http://cnswww.cns.cwru.edu/php/chet/readline/rltop.html) | The GNU Readline library provides a set of functions for use by applications that allow users to edit command lines as they are typed in. Both Emacs and vi editing modes are available. The Readline library includes additional functions to maintain a list of previously-entered command lines, to recall and perhaps reedit those lines, and perform csh-like history expansion on previous commands. |
| [librsync](http://git-scm.com/) | librsync is a library for calculating and applying network deltas, with an interface designed to ease integration into diverse network applications. |
| [libsndfile](http://www.mega-nerd.com/libsndfile) | Libsndfile is a C library for reading and writing files containing sampled sound (such as MS Windows WAV and the Apple/SGI AIFF format) through one standard library interface. |
| [LIBSVM](http://www.csie.ntu.edu.tw/~cjlin/libsvm/) | LIBSVM is an integrated software for support vector classification, (C-SVC, nu-SVC), regression (epsilon-SVR, nu-SVR) and distribution estimation (one-class SVM). It supports multi-class classification. |
| [LibTIFF](http://www.remotesensing.org/libtiff/) | tiff: Library and tools for reading and writing TIFF data files |
| [cURL](http://curl.haxx.se) | libcurl is a free and easy-to-use client-side URL transfer library, supporting DICT, FILE, FTP, FTPS, Gopher, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3, POP3S, RTMP, RTSP, SCP, SFTP, SMTP, SMTPS, Telnet and TFTP. libcurl supports SSL certificates, HTTP POST, HTTP PUT, FTP uploading, HTTP form based upload, proxies, cookies, user+password authentication (Basic, Digest, NTLM, Negotiate, Kerberos), file transfer resume, http proxy tunneling and more. |
| [DMTCP](http://dmtcp.sourceforge.net/index.html) | DMTCP (Distributed MultiThreaded Checkpointing) transparently checkpoints a single-host or distributed computation in user-space -- with no modifications to user code or to the O/S. |
| [duplicity](http://duplicity.nongnu.org/index.html) | Encrypted bandwidth-efficient backup using the rsync algorithm. |
| [EasyBuild](https://easybuilders.github.io/easybuild) | EasyBuild is a software build and installation framework written in Python that allows you to install software in a structured, repeatable and robust way. |
| [expat](http://expat.sourceforge.net/) | Expat is an XML parser library written in C. It is a stream-oriented parser in which an application registers handlers for things the parser might find in the XML document (like start tags) |
| [Ghostscript](http://ghostscript.com) | Ghostscript is a versatile processor for PostScript data with the ability to render PostScript to different targets. It used to be part of the cups printing stack, but is no longer used for that. |
