Graphviz is a free, open source graph visualization tool in constant development since 1988. It represents structural information as diagrams of abstract graphs and networks.

The Networked Corpus is a free, open source tool for navigating a corpus of plain text files via topic modelling using MALLET. The tool consistes of a Python script, and generates a collection of HTML files that can be explored further via the user's web browser. To use The Networked Corpus, users must have a minimum of Python 2.7.x, NumPy, SciPy and MALLET 2.0.7 installed on their system.

Scrapy is an open source programming library for web crawling and web page text extraction, written in Python. You can make calls to Scrapy code from within your own scripts and applications to automate the task of extracting data from websites.

You would typically use Scrapy to automate the task of visiting one or more web pages, on a website to which you have access. You could alternately use it to invoke web-based Application Programming Interfaces (APIs).

Scrapy can download everything it encounters or selected information. One of its capabilities is being able to extract structured data from web pages, such as one or more individual pieces of text from specific locations on the page, or all of the data in a table.

Pattern is a web mining module for Python. It has tools for:

• Data Mining: web services (Google, Twitter, Wikipedia), web crawler, HTML DOM parser
• Natural Language Processing: part-of-speech taggers, n-gram search, sentiment analysis, WordNet
• Machine Learning: vector space model, clustering, classification (KNN, SVM, Perceptron)
• Network Analysis: graph centrality and visualization.

A Python-based XML web publishing framework which enables dynamic pipelining of XSLT transformations. Data is processed by an XML pipeline composed of several WSGI applications and middleware components.

Features:

Apache Cocoon Sitemap 1.0 compatible

WSGI modularity

URI pattern matching

A free (under the GNU General Public License) toolkit for the development of document image recognition systems.

Features:

Custom dictionaries may be created to assist with analysis of specific record types

Extensible functionality

Optical character recognition (OCR) toolkit plugin

Apache Subversion Version System (SVN) is an open source version control system. Access and revision to objects are carefully controlled, to prevent unauthorized access and alteration. Developers use SVN to maintain current and historical versions of files such as source code, web pages, and documentation.

Their Vision:

Subversion exists to be universally recognized and adopted as an open-source, centralized version control system characterized by its reliability as a safe haven for valuable data; the simplicity of its model and usage; and its ability to support the needs of a wide variety of users and projects, from individuals to large-scale enterprise operations.

Features:

Version support for all files and directories in repository, enabling administrator to track changes that have occurred and obtain earlier versions of files

Renamed/copied/moved/removed files retain full revision history

Free-form versioned metadata

Atomic commits

Merge tracking

File locking

Changelists to organize commits into commit groups

Preservation of file attributes, such as executable and read/write status

Apache network server support with WebDAV/DeltaV protocol

Write-through proxy using WebDAV

Interactive conflict resolution

Repository read-only mirroring

Parsable output, including XML log output

Full MIME support - users can view or change the MIME type of each file, with the software knowing which MIME types can have their differences from previous versions shown

Plone is a powerful, flexible, open source Content Management System (CMS) built on top of Zope application server and CMF.

Features:

- Flexible and adaptable workflow

- Customisable

- Free add-ons

- Versioning, history and reverting content

- Support for multiple mark up formats

- Multilingual content management

- RSS feed support

- WebDAV and FTP support

- WYSIWYG

- Integrates with Active Directory, Salesforce, LDAP, SQL, Web Services, LDAP and Oracle

PostgreSQL is a powerful, open source object-relational database system running on all major platforms. It supports native programming interfaces for C/C++, Java, .Net, Perl, Python, Ruby, Tcl and ODBC among others.

PDFMiner is a Python tool for extracting information from PDFs (not only text, but also information about fonts, encoding, and layout.)