Radio UserLand is a client-side blogging software package from UserLand Software, including an RSS aggregator, outliner and scripting language. Radio was the first commercially available program to enable the "RSS enclosure" method of delivering audio or video files, the basis of what came to be known as podcasting several years later.

The Radio program stores the full content of a user's weblog on the user's computer as well as uploading it to a server. Server space at Userland's radio.weblogs.com site was included in the annual registration fee from the start, and continued after Userland's founder sold most of "weblogs.com" to VeriSign in 2005. Radio users also have the option of uploading their weblog content to a server at another Web hosting service.

Radio blog content can be organized into categories with separate RSS feeds; categories also can be assigned to separate page templates and servers.