Many weblog applications can be downloaded and installed on user systems. Some of these are provided under free-software and open-source licenses, allowing them to be used, modified, and redistributed freely. Others are proprietary software which must be licensed.
Other weblog applications are offered only through their developers' hosts, either free of charge or for a fee. Services are typically limited to hosting of the blog itself, but some services offer the option of using the hosted software to update a blog published elsewhere.
Maintenance through the Internet is a nearly universal feature of weblog software. This is usually done through a browser-based interface, enabling authors to create and update content on the site. Most software also supports the use of external client software to update content using common APIs such as the MetaWeblog API and the Atom Publishing Protocol. Third party developers have created many such clients, allowing bloggers to publish entries using desktop software rather than the web-based interface. The WordPress website has an extensive list of clients that support most APIs (not just WordPress). Examples include ecto and MarsEdit.