I'll skip the first 5 (because those plain suck) and skip to the last (and best) 5 options. First up is Thingamablog. This one has a decent interface, is written in Java and resembles a news client. Cool as it may be, it does not support XML RPC style postings, only direct uploads to ftp.
The next one is JBlogEditor. This one is also written in Java but is no longer actively maintained. I had a hard time getting it to run in the first place as the native SWT libraries in there are meant for 32-bit systems. I tried to get the source from SVN but they have no docs on how to build from source and after finally be able to compile it by writing my own compile and run script (which grabs all dependencies) I found out they use a launch system from Eclipse which I don't know.
The 3rd option it QTM for KDE and I can be brief: it looks way to simple for my taste. I will look into it later on to see if its any good as the version reviewed is way older than the current version.
Next up is Flock. Flock is not so much a dedicated blog editor as a fully intergrated package with a Firefox browser and loads of extra stuff, being the "Community Browser" or something. It works straight out of the box on my system but it is way to heavy for just blogging.
Last up is Bleezer, another Java based blogging client. I've actually used that one before so I know it works. The interface is a bit wonky at times but it works fine. The main issue I had in the past is the fact that on linux, it used the default Look and Feel from Java, which is at this time with Java 1.6.0 still Metal. If you don't know it, it looks horrible - something escaped from a Windows 3.1 system or perhaps ancient Solaris.
I finally found a solution for the skinning problem though: use the command line to tell Java to switch the default L&F. I'm currently using something like this:
java -Dswing.defaultlaf=com.sun.java.swing.plaf.gtk.GTKLookAndFeel -jar Bleezer.jar
The only thing driving me nuts at the moment is the fact that the GTK skin is all wrong. Its a lot better than Metal but the fonts are way too small. I have the feeling that this is an issue with the fact that the Qt-to-GtK bridge that I have on my computer is broken because of KDE4 (and thus Qt4.x). At least it is better than nothing and right now I'm even typing this using Bleezer so everything is all good.
I still have high hopes for KBlogger but as long as the 1.0 branch is alpha I will stay clear as it seems to have loads of issues and I can't get it to compile at all.