Perl Elements to Avoid and “What are some best practices in programming that I should adopt?” - mention other good practices.
tidyall - an all-in-one linter, validator and tidier.
check-all-the-things - another all-in-one checker, this time from the Debian project.
Mozilla Developer Network (MDN) - Recommended reference and tutorials for Web technologies.
HTML Dog - Recommended HTML, CSS, and JavaScript tutorials.
List of tools for static code analysis - on Wikipedia.
Canonical URL for the document - on Shlomi Fish’s home site. That page should validate as XHTML5.
GitHub repository - contains the DocBook sources, an issue tracker and more resources. Contributions are welcome. Currently, that page does not validate, but it appears to be GitHub’s fault.