Though WordPress is a superb CMS when it comes to blogging, you might find yourself looking for an alternative. There are plenty of options out there, as you can see below, so all you need is check them out and see if you’re interested in anything.

Before checking them out, you should know a few things that you need to look for:
if it’s secure. Look in forums and reviews, search with google for any information about hacked blogs that use that CMS
if it’s supported and still worked on
how active is the webmaster community behind it. New plugins and themes are made by the community, so you need to have an active group that support the software.
make a list of pro’s and con’s of the software when compared with WordPress
test it yourself on a sub-domain

Here are a few possible WordPress alternatives:
b2evolution
boastMachine
Dotclear
Eggblog
LifeType
Loudblog
Nucleus CMS
sBlog
Serendipity
SimplePHPBlog
Simplog
Textpattern
WB News
Wheatblog
WikyBlog
ZompLog

Enjoy the search!