Simple and extremely useful. URLinfo is a tool for handling web pages: finding information about it, finding headers, internal and external links, etc…
For debug, SEO, extract links.. with google server (Google App Engine)
Beautiful Soup is an HTML/XML parser for Python that can turn even invalid markup into a parse tree. It provides simple, idiomatic ways of navigating, searching, and modifying the parse tree. This class turns HTML into a tree-like nested tag-soup list of Tag objects and text snippets. A Tag object corresponds to an HTML tag. It knows about the HTML tag’s attributes, and contains a representation of everything contained between the original tag and its closing tag (if any). It’s easy to extract Tags that meet certain criteria.
It commonly saves programmers hours or days of work!