It has a built-in editor for structure/similarity searching, plus JMol and AstexViewer. Because this is a Java application, it may run slow at the beginning of your session while JRE initializes. If you continue to have problems with WebCSD running too slowly, please refer to the FAQ page for possible solutions.
WebCSD is not a complete substitute for the Cambridge Structural Database DVD that you can download from the CSD page at UCLA. Power users should download and install CSD on their own computer as well.