Calc is arbitrary precision arithmetic system that uses a C-like language. It's useful as a calculator, an algorithm prototype, and as a mathematical research tool. More importantly, calc provides a machine-independent means of computation. Calc comes with a rich set of builtin mathematical and programmatic functions.
Recoll is a personal full text desktop search tool based on Xapian. It provides an easy to use, feature-rich, easy administration interface with a Qt-based GUI. Text, HTML, PDF, PostScript, MS Word, OpenOffice, Wordperfect, KWord, Abiword, maildir, and mailbox mail folder formats are supported, along with their compressed versions and quite a few others. Powerful query facilities are provided. Multiple character sets are supported, and internal processing and storage uses Unicode UTF-8. Stemming is performed at query time and the stemming language can be switched after indexing.
msmtp is an SMTP client with a sendmail compatible interface. It can be used with Mutt and other MUAs. It forwards messages to an SMTP server which does the delivery. Features include various SMTP AUTH methods, TLS/SSL-encrypted connections (including support for client certificates), support for multiple accounts, DSN, and IPv6 support.
DOLFIN is the C++ interface of the FEniCS project for the Automation of Computational Mathematical Modeling (ACMM), providing a consistent PSE (Problem Solving Environment) for solving ordinary and partial differential equations. Key features include a simple, consistent and intuitive object-oriented API; automatic and efficient evaluation of variational forms through FFC; automatic and efficient assembly of linear systems; and support for general families of finite elements.
Hiawatha is a secure and advanced Web server for Unix. It has been written with security as its main goal. It features advanced access control, prevention of SQL injection and cross-site scripting, banning of clients who try such exploits, the ability to run CGIs under any UID/GID you want, and many other features. These features make Hiawatha an interesting Web server for those who need more security than what the other available Web servers are offering. Hiawatha is also fast and easy to configure.
Ch is an embeddable C/C++ interpreter for cross-platform scripting, shell programming, 2D/3D plotting, numerical computing, and embedded scripting. It is the simplest solution to numerical computing and visualization in the domain of C/C++. It supports the ISO 1990 C Standard (C90), major features in C99 (complex numbers, variable length arrays or VLAs, type generic functions, long long data type, etc), classes in C++, and extensions to the C language like nested functions, string types, etc. It can be embedded in other applications and hardware and used as a scripting language. C/C++ code is interpreted directly with no compilation to intermediate code. It supports Linux, Windows, MacOS X, Solaris, HP-UX, and FreeBSD.