This is a really handsome XML editor, which will surely help you while learning the basics of XML, or mastering your XML files and stylesheets. Features:

• Color-coded XML, DTD, and XSLT editing
• Structure navigator and trace window
• Check well-formedness and validate
• Stylesheet testing with almost any XSLT engine
• XPATH testing
• Customizable "Code Bits" library
• XML formatting via Tidy
• Small download, small footprint

Dia is designed to be much like the commercial Windows program 'Visio'. It can be used to draw many different kinds of diagrams. It currently has special objects to help draw entity relationship diagrams, UML diagrams, flowcharts, network diagrams, and simple circuits. It is also possible to add support for new shapes by writing simple XML files, using a subset of SVG to draw the shape.

It can load and save diagrams to a custom XML format (gzipped by default, to save space), can export diagrams to EPS or SVG formats and can print diagrams (including ones that span multiple pages).

There are also tons of extensions and third-party apps in connection with Dia - there are code structure generators, database structure-to-diagram interfaces and a lot more - don't be shy, go and explore!

This is one of the best tools to manage your PostgreSQL databases. Features in a nutshell:

• Multiplatform (Windows, Linux, FreeBSD)
• Multilingual interface
• Powerful query tool with color syntax highlight
• Access to all PostgreSQL objects (Aggregates, Casts, Columns, Constraints, Conversions, Databases, Domains, Functions, Groups, Indexes, Server-side languages (like PLpgsql, PLpython, PLperl, etc...), Operator classes, Operators, PostgreSQL servers, Rules, Schemas, Sequences, Tables, Trigger function, Types, Users, Views)
• Multibyte support and tons of encodings supported

The Regex Coach enables you to try out the behaviour of Perl's regular expression operators (namely m//, s///, and split) interactively and in "real time", i.e. as soon as you make changes somewhere the results are instantly displayed. You can also query the regex engine about selected parts of your regular expression and watch how it parses your input. Of course, this application should also be useful to programmers using Perl-compatible regex toolkits like PCRE (which is used by projects like Python, Apache, and PHP) or CL-PPCRE. Also, Java's regular expressions and those of XML Schema are very similar to Perl's.

The regular expression editor is a module allowing you to test your PCRE with PHP in a very efficient way. It wraps preg_match, preg_match_all, preg_replace and preg_quote functions, and offer a visual GUI where you can tweak your regular expression easily.