soupault 2.5.0 offers some features that are unique among SSGs.
There are two new built-in widgets for rewriting internal links, which is useful if you don’t host your website at the server root. For example, if you host it at example.com/~user, you cannot just write <img src="/header.png">: it will point to example.com/header.png while you want example.com/~user/header.png instead.
The relative_links widget will convert all internal links to relative links according to their depth in the directory tree. For example, suppose you have <img src="/header.png"> in your page template. Then in about/index.html that link will become <img src="../header.png">; in books/magnetic-fields/index.html it will be <img src="../../header.png"> and so on. This way you can move the website to a subdirectory and it will still work.
The absolute_links widget prepends a prefix to every internal link. Conceptually similar to the site URL option in other SSGs and CMSes, but works for all links, not only links generated by the SSG itself.