I’ve been using emacs-muse during several years now to keep a personal knowledge base in the form a local wiki. To me, the killer feature of emacs-muse is its ability to create links to other documents, mails, URLs or any other resource accessible via Emacs (which is to say, virtually any resource). Combined with planner mode, one has a pretty good PIM system that, among many other virtues, is based on plain text files (and, therefore, is easily indexable) and is as portable as Emacs itself.
Emacs-muse is pretty neat, but not perfect. My main quibble with it is that it’s a major mode. That means that, in order to create a link to other resource, you must be in a ‘muse’ document (a sort of wiki page). But wouldn’t if be nice if you could create links in any document. Say you’re writing source code an want to reference another file in the project, or an HTML page detailing an API you’re using, or a PDF with your projects requirements. Or you’re writing an essay in LaTeX and want to link to a text file of related notes, or an email, or… you get the idea. What I’m asking for is, in emacs parlance, a minor mode providing the linking functionality.
As it often happens in the Emacs universe, my prayers have been heard. Linkd is exactly the package i wanted. In the words of its author, David O’Toole, “linkd-mode is a hypertext system for organizing and interlinking all resources available to GNU Emacs. It can be used to make a “personal web” out of all your text files—regardless of file format or major mode.” In addition, linkd trims off some of the features I rarely use in emacs-muse, namely, the publishing functionality.
Although still in alpha, linkd looks already pretty good, with such niceties as proxy icons in links, as shown in this picture:
Other interesting features of linkd include its ability to mark blocks inside any file that can be link targets, and its tagging functionality. In addition, the list of planned features (searching and indexing, summarize, synthesize links a la remember-mode) makes linkd a package definitely worth exploring and keeping an eye on.