To the best of my knowledge, none of the mainstream blogging services have this built in. It is a function of design and template. I would go with Wordpress ^[1] because it is the best. For code formatting:

1. Design your own styles and functionality if you are up to the challenge
2. Check out the SyntaxHighlighter ^[2] JavaScript project (used by Hanselman ^[3]). You should be able to integrate this pretty easily into any blogging system. (See my blog post ^[4] on integrating this with WordPress).
3. Use Windows Live Writer ^[5] with the Insert Code ^[6] plugin (this will automatically format the code that you paste in properly and post it right to your blog. See here for an example).

Note: If you want to have the most flexibility for constructing your blog template and functionality as you want it to be, you would need to use Self-hosted WordPress.org ^[7], not the hosted WordPress.com ^[8].

I was just looking at the Wordpress Plugins ^[1] and came across the WP-Syntax plugin ^[2].

WP-Syntax provides clean syntax highlighting using GeSHi -- supporting a wide range of popular languages. It supports highlighting with or without line numbers and maintains formatting while copying snippets of code from the browser.

In my opinion, Blogger is the best hosted blog solution. It's free, you can have your own domain name, and you can totally customize the template. I'd check out the SytaxHighlighter like several other people here have mentioned. If you need a place to host js and other files, get an Amazon S3 ^[1] account, and use the S3 Organizer FireFox plugin ^[2].

Steer clear of hosted Wordpress. It is terrible. You cannot customize anything without paying for it.

One more thing that not many people pay attention to: If you want to have the best template to show code, I'd find one with a liquid layout. That way your code "box" can grow larger when the reader resizes their browser.

Thomas Levesque hinted at the answer in his comment on the "correct answer", but it wasn't really clear.

Maybe this will help others:

The following works perfectly in WordPress on a free blog with no plugins, scripts, or hassle.

[code lang="vbnet"]

    Dim things As New List(Of Thing)

[/code]

Alternately, this also works:

[sourcecode language="vbnet"]

   Dim things As New List(Of Thing)

[/sourcecode]        

I suppose you're a programmer if you're lurking here :-) Then I would advise to host Wordpress (or any other blog software) yourself. Not at home, mind you, but on any of the cheap hosting companies around. I won't recommend mine as it's in France, a bit too far away.

There are two main reasons:

• You will be the master of your domain name: when you want to change hosting company or software, you will be able to do so. You don't want to change your domain name when you have thousands of readers and a Google PageRank of 5.
• You will be able to customize your software (with little effort) to add the many plugins available.

A few links on the subject:

• Choosing a Blog Platform ^[1] on ProBlogger
• Migrating your Blog Between Platforms: Pitfalls and Consequences ^[2] on ProBlogger
• Starting a new blog? Get your own domain name! ^[3] by Emily Robbins in a self-demonstration

Cheers

You can convert the code into html with syntax highlighting before posting it to your blog. For example in vim you can use the :TOhtml ^[1] command.

Also you can use GeSHi ^[2] . The WordPress plugin WP-Syntax ^[3] uses GeSHi, but you can also use GeSHi offline.

As a few people have already mentioned, I use SyntaxHighlighter ^[1] on my blog. The only issue I had with it is that my markup wouldn't be valid if I followed the instructions from the SyntaxHighlighter usage wiki. To fix this problem I added some simple jQuery code before SyntaxHighlighter scans my document:

$(document).ready(function() {
    $('pre.code').attr('name', 'code').removeClass('code');
    dp.SyntaxHighlighter.ClipboardSwf = 'clipboard.swf URL';
    dp.SyntaxHighlighter.HighlightAll('code');
});

Instead of adding the name="code" attribute to my <pre/> tags, I add a 'code' class to my pre tags before I add my language attribute so my class attribute looks like this:

 <pre class="code css">

 </pre>

And my javascript code adds the 'name' attribute and removes the 'code' class dynamically so that my markup validates and works flawlessly with SyntaxHighlighter.

Mango Blog ^[1] and BlogCFC ^[2] both support code blocks out of the box, using the code tag:

<code></code>

Both are CFML applications, so you'll either have to get some ColdFusion hosting, or run one of the open source alternative engines: Railo ^[3], OpenBD ^[4], (and it's there, but probably not full-featured enough to run these apps: The Smith Project ^[5])

I use and recommend WordPress. You can start off with a hosted WordPress blog and move it off to another hosting provider if you want to take advantage of the great number of plug-ins available. With a hosted blog, you can only use the plug-ins that WordPress makes available to you.

...and use Windows Live Writer for writing/publishing. There are several nice code formatting plug-ins available for WLW.

I use WordPress with the "Code Markup" plugin. It has worked really well. You just surround the code in your posts with

<pre><code>code here</code></pre>

How about BlogTrog ^[1] Code Window?

I use Gist ^[1] on my wordpress site. I tried the other Syntax highlighting plugins, but they never quite worked as well as I wanted.

It doesn't exist as standard, being somewhat niche, but there are plenty of nice scripts out there to help format. The best one I've seen (which is what Yahoo! use on their YUI pages) is SyntaxHighlighter ^[1].

Of course, given how nice the Stack Overflow boxes are for doing code, you might want to look at how they do things and "port" it to Blogger ;)

I second Yaakov Ellis ^[1] - I personally use Windows Live Writer and Insert Code.

I really got into PHP programming thanks to Wordpress and would recommend it in a heartbeat. Active developer community, plugins and tutorials galore and it's a cinch to install.

copy and paste into word from visual studio. Then from word, copy and paste into your blog.

I use Chyrp ^[1] because it's lightweight and easy to use. For code formatting you can use the Geshify ^[2] module or my own code feather ^[3].

CodeHTMLer ^[1] is a simple program that translates plain text code into a colorized HTML version of the code.

If you use TextMate in Mac OSX, BitButter has a great post ^[1] on how to display your TextMate code (formatting included) in WordPress.

Code Markup ^[1] is another Wordpress Plugin.

Squarespace ^[1] has a really nice admin interface, the best in the industry as far as I am concerned.

I just want to add CodeColorer ^[1] plugin for wordpress. It works really well. It has an option for escaping html entities and supports a lot of languages. Check you can see it in action on this post ^[2]