Emacs package Geiser improves Scheme development

Geiser is a great tool for working with Scheme, and the author jao (José A Ortega Ruiz) is a genuinely good guy. His old blog at<p><a href="http://programming-musings.org" rel="nofollow">http:&#x2F;&#x2F;programming-musings.org</a><p>is full of Scheme goodness, and he has another site devoted to Emacs hacks at<p><a href="http://emacs.wordpress.com" rel="nofollow">http:&#x2F;&#x2F;emacs.wordpress.com</a>

Can anyone elucidate on the main differences between Slime and Geiser? The Geiser main page says that Slime is&#x2F;was part of the inspiration but others are also mentioned.