Greg Gonzalez (blog | twitter) of SqlSentry, last night released a very cool new and free product.  Plan explorer is a tool for examining query plans and overcomes many of the limitations of viewing plans within Management studio.  If you view plans a lot i would recommend that you give it a try.

This is by no means the only free product available for SqlServer,  in no particular order here are some others that I use on a regular (and not so regular) basis.

Mladen Prajdic  (blog | twitter)  has produced the wonderful SSMS ToolPack which extends the functionality of management studio and can be a real life saver.

For large trace files , being able to see the wood for the trees, can be hard.  ClearTrace normalizes a trace file to help you analyse the the calls to procedures and adhoc statements.

Codeplex is a Microsoft site where anyone can release software.  Some of these are by Microsoft support staff to aid them with their roles and although not fully supported are still well worth a look at.  Notable packages are

• Performance Analysis of Logs (PAL)
• SQLNexus – Analyse performance data   
• Central Management System  - Roll your own SqlServer monitor
• Business Intelligence addin (BIDS Helper) for developer studio 
• SSRS Explorer – Manage SSRS installations a little easier
• Kimball Slowly changing dimension by Todd Mcdermid (blog|twitter) – about a million times better than the standard SSIS SCD

One other Microsoft package that you should look at are Performance Dashboard reports.

Another company who is heavily involved in the SqlServer community is Red Gate.  They have a free SQLSearch tool which is a SSMS plugin to aid text searching through procedures , triggers , table structures etc.  As well as producing tools they also have a number of other resources available to download.  To pick just three , Defensive Database programming by Alex Kuznetsov (blog|twitter), SqlServer Execution plans by Grant Fritchey (blog|twitter) and the DMV Starter Pack. 

If you need to find all the Sqlserver installs at your site, Quest Software have Discovery Wizard for Sql Server currently available as free beta release.

Before releasing software live , its always wise to test the scalability.  To that end, you may want to use Adam Machanic’s (blog|twitter) Sql Query Stress tool.  Also from Adam is his WhoIsActive ? script.  Other scripts which I find useful are Michelle Ufford’s (blog|twitter)Index Defrag and Brent Ozar’s(blog|twitter) Blitz Script for when you have just been handed a server you knew nothing about.

Finally get involved in Twitter,  its a fabulous resource with many of the best SqlServer professionals regularly using it.  Brent has a simple all you need to know about twitter guide here.

Disclaimer : This is all for information only, I cannot be held responsible if any tool does not operate as expected.