Experimentally I tried to add OpenSearch and Sherlock search engine support to my blog.

OpenSearch

OpenSearch is supported by Firefox 2+ and IE 7. Resources:

• http://en.wikipedia.org/wiki/OpenSearch
• http://www.opensearch.org/Specifications/OpenSearch/1.1#OpenSearch_description_document

I created an OpenSearch description file and uploaded it on my blog: opensearch.xml (xml, 1 KB)

Sadly I cannot add the file to the layout itself, so there is a bit of dependency between the layout used and the files in the blog the layout is applied to.

A reference to the OpenSearch description file must be added to the HTML head by updating your layout's main page:
<link rel="search" type="application/opensearchdescription+xml" href="<% site.url %>getfile?name=opensearch.xml" title="OpenSearch <% site.title %>" />

Browsing my blog should add a search engine option to Firefox and IE.

Sherlock

Sherlock is a searching tool developed by Apple.
Resources:

• http://en.wikipedia.org/wiki/Sherlock_(software)
• http://developer.apple.com/technotes/tn/tn1141.html

Sherlock plugin description file: sherlock.src (src, 1 KB)

Sherlock untested yet.

Update: No success adding sherlock support, probably already outdated? Will stop trying

Internet Explorer and Firefox (and probably other browsers as well) support an RSS feed icon being activated/displayed if a webpage offers a rss feed. The default antville.org layout already provides a link but due to a false mime-type its not recognized by Firefox or IE. Add the following link tag to your HTML headers in main page layout:
<link rel="alternate" type="application/rss+xml" title="<% site.title %>" href="<% site.url %>rss">

cf. http://en.wikipedia.org/wiki/RSS#Including_in_XHTML