CVSsuck is a mirroring tool for CVS repositories. Unlike other tools such as CVSup or rsync, it uses cvs command to access the repository. So, it works well with remote repositories without a special server or shell account. However, it is inefficient because the CVS client/server protocol is not designed for mirroring.
SWIG is a software development tool that connects programs written in C and C++ with a variety of high-level programming languages. SWIG is primarily used with common scripting languages such as Perl, PHP, Python, Tcl/Tk, and Ruby, however the list of supported languages also includes non-scripting languages such as C#, Common Lisp (CLISP, Allegro CL, UFFI), Java, Modula-3, OCAML, Octave, and R. Also several interpreted and compiled Scheme implementations (Guile, MzScheme, Chicken) are supported. SWIG is most commonly used to create high-level interpreted or compiled programming environments, user interfaces, and as a tool for testing and prototyping C/C++ software. SWIG can also export its parse tree in the form of XML and Lisp s-expressions.
QuantLib is a cross-platform, quantitative finance C++ library for modeling, pricing, trading, and risk management in real-life. It is also wrapped as Python/Ruby/Scheme modules. Extensions for Excel, R, and Mathematica are available. Other such extensions are under consideration. QuantLib offers tools that are useful both for practical implementation and for advanced modeling. It features market conventions, yield curve models, solvers, PDEs, Monte Carlo (low-discrepancy included), exotic options, VAR, and so on.
MPI Ruby is a Ruby binding of MPI. The primary goal in making this binding was to make the power of MPI available to Ruby users in a way that fits into the language's object oriented model. In order to do this, the buffer and datatype management necessary in the C, C++, and Fortran bindings have been removed. What this means is that MPI Ruby allows you to treat objects as messages. MPI Ruby also aims to be a complete binding to MPI, in that it offers access to nearly all functionality of MPI.
PhysicsFS is a library to provide abstract access to various archives. The programmer defines a "write directory" on the physical filesystem. No file writing done through the PhysicsFS API can leave that write directory, for security. For file reading, the programmer lists directories and archives that form a "search path". Once the search path is defined, it becomes a single, transparent, hierarchical filesystem. This makes for easy access to ZIP files in the same way as you access a file directly on the disk, and it makes it easy to ship a new archive that will override a previous archive on a per-file basis. Symbolic links can be disabled, for added safety. Finally, PhysicsFS gives you a platform- abstracted means to determine if CD-ROMs are available, the user's home directory, where in the real filesystem your program is running, etc.
MetaRuby contains miscellaneous libraries (useful now) for a future Ruby-in-Ruby interpreter including Array/Hash/String as abstract ("Hollow") classes, an undo queue, a statistical time-profiler, an event loop, a modular marshaller ("ToSource"), a specification for a modular+reflexive+homoiconic remote call system ("LGRAM"), a declarative type system, a schema for expressing Ruby source code as proper (non-special) Ruby objects, etc.