Horde and Roundcube are both Webmail based email programs. When you create email accounts within your Shawna Leigh Designs hosting account (cPanel), you have the option of checking your email using either of these programs by visiting yourdomain.com/webmail
Accessing your emails via Webmail is great if you're on the go, since all you need is an internet connection and a web browser.
When you login to Webmail at yourdomain.com/webmail, you have the option to choose which email program you want to use. You can switch back and forth between Horde and Roundcube at anytime. Once you find the one that you prefer, you can set it as the default program.
Here's a quick overview of the differences. I recommend Horde, but as I mentioned, you can try both of them yourself to make your own decision.
|Application Official Website
||The Horde Project||Roundcube Webmail Project|
|Recommended For||Users who need a full suite of features that includes mobile email access and advanced productivity tools.||Users who need a user-friendly web interface with some additional features available.|