Graphical design of primers for PCR

 PerlPrimer is a free, open-source GUI application written in Perl that designs
 primers for standard Polymerase Chain Reaction (PCR), bisulphite PCR,
 real-time PCR (QPCR) and sequencing. It aims to automate and simplify the
 process of primer design.
 .
 If operated online, the tool nicely communicates with the Ensembl
 project for further insights into the gene structure, i.e., allowing
 for taking the location of exons and introns into account for the design
 of the primers. The sequences themselves can be retrieved, too.