The Exchange toolkit

Here's a great blog post from Chad Solarz over at the Technet blog.

Even tho the post itself is last updated may 2013 it is the biggest collection of tools I've seen so far .
View the post here.

Short summary of the tools listed:

VSSTester Script – Exchange 2010
MFCMAPI – Any version
Experfwiz – Exchange 2007 & higher (soon to be 2013 as well)
PAL – Any version
EWS Editor - Exchange 2007 and up
OffCat (now ver 1.2)– outlook 2003 and higher
Network Message Analyzer – Any version
Microsoft Script Center Repository – Any version
Exchange Remote Connectivity Analyzer – All versions
Autodiscover Self Test – Exchange 2007 and up
Exchange Client Network Bandwidth Calculator – Any version
CalCheck tool – Outlook and Exchange 2003 and higer
Datacenter Switchover Troubleshooter – Exchange 2010
Log Parser Studio 2.0 – Any version
Exchange Legacy API Scanner – Exchange 2010
Exchange Pre-Deployment Analyzer
Exchange Deployment Assistant (EXDeploy)
Exchange Mailbox Server Calculator – 2010 / 2013
Exchange Processor Query Tool
Microsoft Connectivity Analyzer Tool – Any version
Exchange Server User Monitor (ExMon) – Exchange 2000 and higher
Exchange Server Profile Analyzer – Exchange 2007
Exchange get file log usage script - Exchange 2007 +
Public Folder Replication Troubleshooter – Exchange 2003
PST Capture tool – Exchange 2010 & 2013
LoadGen – Exchange 2010
JetStress – Exchange 2010 (soon to be 2013 as well)
TCPView – All versions
PortQry UI – All versions
EAS Troubleshooter script - all versions
Report CAL information script - Exchange 2010
Exchange Log Growth Collector Script -  Exchange 2007 & 2010
Process Tracking Log (PTL) tool - Exchange 2007 & 2010
ActiveSync Guided walk-through - non-version specific
Outlook connectivity guided walkthrough - Exchange on-premises
Exchange 2003 Migration Toolkit - Exchange 2003
Office365 Mailbox Migration perf analysis - Hybrid / migration to the cloud
ActiveSync log analysis - All versions of Exchange
Exchange DB growth script - Exchange 2010 & 2013
Office 365 Mailbox / Folder sharing scenarios - Office 365 AND Exchange on-prem
Exchange Online migration guided walkthrough - Any on-prem to Office 365
Exchange Client Performance Analyzer
IMAP Migration walkthrough troubleshooter