Am assuming Sybase ASE.
Ships with Sybase Central and SQL Advantage as part of the client tools. Sybase Central lets you manage and create tables, views, sprocs etc. SQL Advantage lets you run SQL...
Sybase Workspace is a new tool for ASE, I ve never tried it. http://www.sybase.com/products/modelingdevelopment/workspace
ASE ISQL is a free tool that is also useful for running sql, but is less useful for modifiying stored procedures etc. (More of a SQL Advantage replacement). http://code.google.com/p/aseisql/
If you have money to spend then there s also Embarcadero s DBArtisan. http://www.embarcadero.com/products/dbartisan. I ve used this and it s pretty good, although their support for MSSQL and Oracle is better than the Sybase support.