Performance tuning in Sybase Does Sybase have a tool like AWR in Oracle which can be used to identify high load SQL, tell the important waits that are happening, help in understanding the workload? 
What are the main tools to be used to identify high load SQL and tune query performance?
Not specifically like AWR, but there are a number of built-in tools that can be deployed.

The "mda" tables will be your best friends for identifying poorly performing queries.

Rob Verschoor's site has detailed information on how to use them along with some pre-built tools.

http://www.sypron.nl/mda.html

Official documentation can be found here:
http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.infocenter.dc70002.1570/html/title.htm

sp_sysmon, monserver and historical server may be of little use. They're more suited to server configuration.