refdb was designed with the fact in mind that good applications are out there for almost any purpose. Therefore it relies on a few external applications which have to be properly installed. The following list shows the applications which are absolutely required and some applications which will make your life easier.
refdb uses MySQL as its database engine. This SQL database engine is widely used in the web business and is highly regarded for its speed and stability. MySQL runs on a wide variety of Unix- and Unix-like operating systems as well as on Windows. Newer versions of MySQL have been released under the GNU Public License and are available for free in either source-code or binary packages at the MySQL homepage.
Jade is a freely available and well-proven DSSSL engine. refdb uses Jade both to extract the IDs of the references which are cited in a SGML or XML document and to transform SGML and XML documents using DSSSL stylesheets. Jade is available on James Clarks homepage. Prebuilt binaries are available for some platforms, and it builds out of the box on quite a number of platforms. Jade has seen some further development by an independent group of programmers. These newer versions were released as OpenJade and are available at the OpenJade homepage. Instructions to build OpenJade on Windows NT/Cygwin and precompiled binaries are available here (official Cygwin packages of OpenJade and related tools are in preparation).
Note: OpenJade has some advantages over Jade for our purposes. If it is possible to obtain or compile OpenJade on your platform, you should go for it. Both Jade and OpenJade can be installed on the same machine without conflicts. The configure script will look for both OpenJade and Jade and will use the former as the default DSSSL engine in the shell script customizations if it is available.
Please be aware that you need Jade or Openjade even if you plan to use only XML documents. Currently there is no way to extract the citations from an XML document "the XML way" (not that this would be terribly difficult, it's just not done yet).
If you're working with XML documents and want to transform them using the XSL stylesheets, you'll need some sort of XSL processing machinery. Popular choices are Xalan, Saxon, and xsltproc. The Java-based tools among these need the Java Virtual Machine installed, of course. Generating printable output seems to work best through the TeX path (see below) using the PassiveTeX macros.
refdb ships with DSSSL stylesheets for DocBook SGML/XML documents, XSL stylesheets for DocBook XML documents, and XSL stylesheets for TEI XML documents. All these are not standalone stylesheets, but driver files for the respective stylesheets by Norm Walsh and Sebastian Rahtz. These must be installed on your system if you want to transform DocBook or TEI documents.
Donald Knuth's famous typesetting system is available on almost any platform. You need a TeX system to generate LaTeX bibliographies. It is also convenient to generate nice-looking printable output from SGML and XML documents.
This is nothing to worry about if you use some flavour of Unix or Linux: anything that lets you edit texts will do. However, if you have to use Windows, you should be aware that many run-of-the-mill Windows text editors are not suitable for use with refdb as they are not able to handle the Unix-style line endings (LF instead of CR/LF) properly. The standard Windows editors Notepad, WordPad, and MS Word will not work unless you use a DOS to Unix conversion filter like dos2unix. These line endings are important in almost all cases, especially when uploading and editing references. Some freeware or shareware text-editors for programmers have an option to read and write Unix-style line endings. A few popular Unix text editors are available as Windows ports. Among them are vi clones like vim which is available as a native Windows application and as a Cygwin version, as well as Emacs. GNU Emacs is available as a native Windows application, whereas XEmacs can both be built as a native application and as a Cygwin program.
If you plan to create bibliographies, you may need a SGML/XML editor for two reasons. First, the bibliography style specifications have to be written as SGML or XML documents (unless someone else has contributed such a file). Second, if you want to create bibliographies for DocBook documents, you want to use a SGML/XML editor anyway. But SGML is plain text after all, so SGML/XML editors make your life easier, but they are not strictly necessary to get something done.
Emacs/XEmacs and the PSGML mode excel as an editor for both SGML and XML files. This combo should be the first choice as it is very powerful and freely available.
Most likely you will not have a hard time to find some kind of web browser on your system. A web browser may be more pleasant to view the query results than the standard output on stdout or a pager. If you use refdb to manage a collection of PDF files, the paths to these files will be displayed in the HTML output and you can open the files with one mouseclick.
If you plan to use the web interface of refdb, you certainly need a web browser to do so. Essentially any web browser available today should do as long as it supports Cookies and JavaScript (this includes Netscape, Mozilla, MS Internet Explorer, Lynx, Konqueror, to name a few).
If you want to run the refdb web interface at your site or on your computer, you need a web server that can handle CGI programs. Apache is the most widely used web server and available for free for almost any platform, including all platforms that refdb currently supports.
The programming language Perl could be called the "workhorse of the internet" and the Perl interpreter is available for almost any platform. refdb currently uses Perl only for a non-mandatory post-processing of bibliography data that you import from BibTeX .bib files. However, the language is well suited to write import filters for other bibliographic data so you may end up needing it anyway.