OligoFaktory is a web-based set of applications for the design, on an arbitrary number of target sequences (such as ORFs), of high-quality oligonucleotides for PCR and micro-array experiments. The plugin-based architecture allows to easily embed new modules: i.e. automated amplicons determination or design methods. The user-centered web interface conforms to state-of-the-art web- standards. An XHTML form is associated with each tool to fetch parameters from the user as input. A unified presentation of results provides overviews with distribution charts and relative location bar graphs, as well as detailed features for each oligonucleotide. Input and output files conform to a common XML interchange file format to allow both automatic generation of input data, archiving, and post-processing of results. We also describe a lightweight queu- ing system that distributes the resource intensive calcutations among multiple hosts.