List popular / top rated software applications (preferably web based) 

1. Used by Lawyers, Solicitors to manage and monitor their practice
2. Used by Doctors, Small hospitals to manage their clinic and patients
3. Used by service workshops to manage and pursue inbound and outbound
client calls or cases

Need link to their websites only, No brief/explanation. Only condition
is that they should be popular / top rated / etc.

For Lawyers, the popular software are:

AbacusLaw, http://www.abacuslaw.com
TimeMatters, http://www.timematters.com/
ProLaw, http://www.thomsonelite.com/solutions/product-fam/prolaw/index.asp
PcLaw, www.pclaw.com/
Tabs3, www.tabs3.com/
Amicus Attorney, www.amicusattorney.com/ 
PracticeMaster, www.tabs3.com/

There is additional software used for docketing and document creation.

At my law firm, we use a web-based solution for keeping track of time,
but it is not one that gets mentioned a lot in legal software circles.