Feature Comparisons in SharePoint Search Versions

I have been asked this question few times by my MOSS Search customers. Question being: What is the difference in features in WSS 3.0, MOSS 2007 and Office SharePoint Server 2007 for Search?

One thing to note is that the Search in the 3 products are all based on the same Microsoft Search core indexing engine. However, there are differences between the 3 SharePoint search versions. This table does a comparison of features in the 3 products:
 

Feature	Search in WSS 3.0	Office SharePoint Server 2007 for Search	Enterprise Search in MOSS 2007
What can be indexed	Local SharePoint content	SharePoint sites, Microsoft Exchange Server content, file shares, Lotus notes, custom content.	SharePoint sites, Microsoft Exchange Server content, file shares, Lotus notes, custom content, line-of-business (LOB) content.
Rich, relevant results	Yes	Yes	Yes
Alerts RSS Did you mean? Collapsing of duplicates	Yes to all	Yes to all	Yes to all
Best bets Results removal, Query reports	No to all	Yes to all	Yes to all
Search Center / Tabs	No	Search Center without Tabs	Search Center with Tabs
People search Knowledge network	No to all	Yes to all	Yes to all
Business Data Search	No	No	Yes
Query Web service	https://<site>/_vti_bin/spsearch.asmx	https://<site>/_vti_bin/search.asmx	https://<site>/_vti_bin/search.asmx
Security trimming of search results	Yes; supports default security trimming only	Yes; supports default security trimming only	Yes; supports default and custom security trimming
Query syntax	Windows SharePoint Services 3.0 Search SQL Syntax Windows SharePoint Services 3.0 Search Keyword Syntax URL syntax	Enterprise Search SQL Syntax Reference Enterprise Search Keyword Syntax Reference Enterprise Search URL Syntax Reference	Enterprise Search SQL Syntax Reference Enterprise Search Keyword Syntax Reference Enterprise Search URL Syntax Reference

For more information, please see this article in the MOSS SDK: https://msdn2.microsoft.com/en-us/library/aa981559.aspx

Hope that helps,
Mike