They are disabled by default, but many people never use them and wonder if they can be deleted.
The short of it is – YES you can delete them. I delete them from all my WordPress installations. I see them both as bloatware.
So what do they do?
Akismet is an anti-spam service, the plugin creates the interface between your website and the service and requires some basic setup to get going.
Since WordPress is fundamentally (but not always) a blogging platform, public comments are common – but this also means spam … lots and lots of spam.
Akismet goes a long way towards tackling comment spam and is recommended if you allow public comments.
But if you have comments disabled or you are using a third-party commenting system like Disqus you can delete the Akismet plugin.
Hello Dolly is a simple plugin that demonstrates how to create a plugin. It was bundled into WordPress back in version 2.7.1 back in February 2009.
It simply adds a line from the song “Hello, Dolly!” to the top of the wp-admin.
Why it was bundled is not clear since it doesn’t exactly serve any real practical purpose.
But by all means, delete it.