Bare XML is a "bare" XML parser with all primary parsing done via a simple state engine with about 20 or so different states. A tree structure is created during parsing, with all node names and values linked via pointers directly into the original text buffer. As such, Bare XML is extremely fast and simple. Currently, the parser is available in a perl module with Perl glue to turn the created tree into a Perl hash tree. The module name is XML::Bare.
The HTML::Defaultify Perl module is designed to allow CGI programmers to present forms with some fields filled in, which is handy for letting users correct bad input, show records to be edited, and much more. The main function, defaultify(), takes any block of HTML and a hash of field names and values, and returns the HTML with the form fields set to those values. Value lists for multiple same-named fields are supported, as are pages with multiple forms. Several different input formats are supported for compatibility with existing tools.
HTML::Mason is a full-featured web site development and delivery system. Mason allows web pages and sites to be constructed from shared, reusable building blocks called components. Components contain a mix of Perl and HTML, and can call each other and pass values back and forth like subroutines. Components increase modularity and eliminate repetitive work. HTML::Mason is most powerful when used in conjunction with mod_perl, but can be used in standalone applications as well.
JSON::XS implements JSON for Perl. Unlike other modules, its primary goal is to encode to syntactically correct JSON and flag invalid JSON while decoding. It ensures round-trip integrity of data types while being intuitive to use. Currently being the fastest of the JSON encoders available for Perl, it supports a variety of format options, such as single-line, ASCII-only, or pretty-printed, and can be tuned for speed or memory usage. It comes with a wealth of documentation describing usage and implementation details.
LaTeX::Table is a Perl module that provides functionality for an intuitive generation of LaTeX tables. It ships with some predefined, good-looking table styles. This module supports multi-page tables via the xtab and longtable LaTeX packages. For publication quality tables, it utilizes the booktabs package. It also supports the tabularx and tabulary packages for nicer fixed-width tables. Furthermore, it supports the colortbl package for colored tables optimized for presentations. The ltpretty program makes it easy to use this module from within a text editor such as Vim or emacs.
This module implements an XML::SAX filter which adds line numbers and column numbers to errors generated by SAX handlers further down the pipeline. It was written so that XML::Validator::Schema could blame the correct line of XML for validation failures. You can use this module to enhance the error messages generated by any SAX handler.
XML::Twig is an XML transformation module. It can be used to process huge documents while still being in tree mode; is not bound by DOM or SAX, so it is very Perlish and offers a very comprehensive set of methods; is simple to use; and DWIMs as much as possible. What it doesn't offer: full SAX support (it can export SAX, but only reads XML); full XPath support (unless you use XML::Twig::XPath); nor DOM support. It is also a big module, and with over 500 methods available it can be a bit overwhelming. A good starting point is the online tutorial.