The ease of publishing to multiple formats is a big plus. I really like the Layout editor and the preview provided to check your setup before publishing.

Paligo is a well thought out database system, with an easy to navigate web-based front end that allows for a variety of output formats.

For a full-fledged technical writer several aspects have to be met by a true Help Authoring Tool (HAT) in order to be ranked into that category. Allow editing of style sheets for formatting and corporate design. Have persistent links. Make reusing of content easy and reliable. Allow the use of variables and the possibility of versioning. Offer what is called Single-Source-Publishing: One place to edit, several common formats to publish to. The tool itself should have a clear structured and responsive as well as fast interface so after learning the basics you can focus on editing, not on the tool. Batch search&replace: There are still tools out there who do not allow that across topics/pages/files, which is dreadful for everyday work. All these should work-out-of-the box, not as additions whose compatibility is doubtful. Paligo does all this, based on the DocBook specifications which in turn are based on XML. That way, in the rare cases you need this, editing the code is clear and easy, too. Paligo's interface features are extremely well-structured, once you got the 'hang' of it you find them with 2 or 3 clicks on the outside. Adding and removing elements, inline images, lists, procedure steps or special heading formats is a breeze! It is fast and stable and the interface looks pleasing, without interrupting the major workflow: Editing. To boot, review and collaboration are easy and stable as well, with inline comments to be worked at in an editing interface or a special review one. I have worked with Wiki-Software pretending to be a 'HAT', as well as with most major HATs out there, at least for testing. Love some well. I rank Paligo among the best out there.