Two Constraints Editor GUIs are available in Foundation to assist with constraining elements of your design to obtain the desired performance.
The Express Constraints Editor is a feature available in the Foundation Express product only. The Express Constraints Editor is a GUI that allows you to set performance constraints, attributes, and optimization controls in the Synthesis phase before you start to optimize a design. Constraint entry is in the form of constraints tables for logically related groups (clocks, ports, paths, modules). Design-specific information based on the architecture specified for the selected version of the design is automatically extracted and displayed in the tables.
The Xilinx Constraints Editor GUI allows you to create and edit certain constraints after the translation step in the Implementation phase of the design without directly editing the UCF (User Constraint File).
You can invoke the Xilinx Constraints Editor by selecting Start 
Programs Xilinx Foundation Series Accessories Constraints Editor.
You can also start the Constraints Editor from the standalone Design Manager by selecting Utilities Constraints Editor.
The Xilinx Constraints Editor is not the same as the Express Constraints Editor available in the HDL Flow and is most useful for schematic and ABEL designs in Schematic Flow projects.
For more on the Constraints Editor, refer to the DynaText online documentation, Constraints Editor User Guide.
