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.
RuStem is a fast Ruby module with the the Porter stemming algorithm (a process for removing the commoner morphological and inflexional endings from words in English; its main use is as part of a term normalisation process that is usually done when setting up Information Retrieval systems).
Berkeley DB XML is a native XML database engine for use within your product. Made available as a C++ library with language bindings for Java, Perl, Python, PHP, and Tcl, it integrates directly into your application (it is not a standalone database server). It provides XQuery access into a database of document containers. XML documents are stored and indexed in their native format using Berkeley DB as the transactional database engine.
AntFlow builds upon Apache Ant to provide a new approach to simplifying system automation that uses pipelines of hot folders chained together to perform a given task. Using XML, it associates an automated task such as data transfer, encryption, or XML processing with a directory on the local system. Whenever a file is copied or written into the hot folder, the associated task is executed and the file is moved to the next hot folder in the pipeline for further processing.
FeResPost is a library that allows the rapid development of small programs for the post-processing of Nastran or Samcef finite element results. The library allows easy manipulation of finite element models, groups, and results. Efficient post-processing is possible because the time-consuming operations are written in C/C++. The library is distributed as a COM component, a .NET assembly, as well as a Ruby compiled extension.
BDDs [bry86] (or more precisely ROBDDs) are efficient data structures for representing a boolean formula. They are widely used in formal verification, in particular symbolic model-checking. Ruby- BDD, based on Buddy, provides access to BDDs from Ruby, a powerful and very easy to use object-oriented language. The purposes are quick prototyping and education.
tbibtools provide a simple regexp-based BibTeX parser that can be used to sort bib files, reformat bib files, list keys in a bib file, and show bib entries matching a regular expression. It is available as both a script and a VIM plugin. It makes a few assumptions about how a bib file should look like.