Blo.gs
Lets you keep an eye on your favorite weblogs via the web, email, and instant messenger.
Blog Oriented Publishing
A database-backed web content management system designed to offer users with limited privledges on their web server the benefits of a sophisticated CMS.
Blogger
Free, automated weblog publishing tool that sends updates to a site via FTP.
Blogspot
Blog*Spot is the turn-key hosting service for Blogger™, the leading personal publishing tool on the web.
Greymatter Weblog/Journal Software
Greymatter is the original opensource weblogging and journal software. With fully-integrated comments, searching, file uploading and image handling, completely customisable output through dozens of templates and variables, multiple author support, and many other features—while having perhaps the simplest installation process and easiest-to-use interface of any program offering this level of functionality—
LiveJournal
LiveJournal is a simple-to-use (but extremely powerful and customizable) personal publishing ("blogging") tool, built on open source software.
Moveable Type
Movable Type is a powerful, customizable publishing system which installs on web servers to enable individuals or organizations to manage and update weblogs, journals, and frequently-updated website content.
Nucleus
Nucleus allows you to easily maintain your own weblog(s) on your own server. It offers a system that is easy to install, but still offers maximum flexibility.
OpenJournal
OpenJournal is a completely Web-based interface (say bye-bye to FTP, manual archiving, etc.). Features include: automated file creation; automated index updating; editing of all files through a Web-based interface; entries with or without titles and time posted; automated archiving based on a weekly or monthly format. All done through ordinary text files and no additional perl modules needed to run it. And it's free.
Personal Weblog System
The Personal Weblog System is a perl script that works as some kind of personal journal and text file station. Think of a very basic weblog tool which get mixed up with a online text editor. The main difference to other weblog systems is, that you add new entries from the same page you read the entries. This page is password protected, that's why it is a "personal" weblog system. And you can add, view and edit your own text files online.
Pivot
Pivot is a web-based tool to help you maintain dynamic sites, like weblogs or online journals. Pivot is released under the GPL so it is completely free to use. It is written in PHP, and does not require additional libraries or databases to function.
Radio Userland
Radio UserLand is a unique and powerful web publishing and weblog tool that is used and praised by many of the world's most accomplished web authors. With advanced features such as an integrated news aggregator, Radio enables users to do far more than is possible with the hosted-only weblog products offered by others. Suitable for personal or business users, Radio UserLand is unmatched when it comes to power and potential uses. Radio is much more than a weblogging tool and comes loaded with features that are easy to use and that will help you customize your online experience, harness the awesome power of the Internet, and accomplish more in less time.
Scoop
Scoop is a "collaborative media application." It falls somewhere between a content management system, a web bulletin board system, and a weblog. Scoop is designed to enable your website to become a community. It empowers your visitors to be the producers of the site, contributing news and discussion, and making sure that the signal remains high.
Textpattern
A flexible, elegant, easy-to-use content management system for all kinds of websites, even weblogs.
Tinderbox
Tinderbox is a personal content management assistant. It stores your notes, ideas, and plans. It can help you organize and understand them. And Tinderbox helps you share ideas through Web journals and web logs.
Web Blog
Written by Leif M. Wright, Web Blog is a very lite blog script. If you're in the mood for a blog and don't want to go through a bunch of gyrations to get one, this is the script for you.
WordPress
WordPress was born out of a desire for an elegant, well-architectured personal publishing system built on PHP and MySQL and licensed under the GPL. WordPress is fresh software, but its roots and development go back to 2001. It is a mature and stable product.