Handling observation proposals for SALT

SALT uses the Principal Investigator Proposal Tool (PIPT) for generating, checking, submitting and editing proposals. The PIPT maps XML into Java classes with immediate error and consistency checking, and thus prevents non-feasible observation requests. Various tools allow the user to simulate SALT observations. These include standard source spectra (e.g. black body, power law, Kurucz model atmospheres), and allow users to add their own library spectra. The PIPT is complemented by the Web Manager for administering submitted proposals. It is discussed how the code of these tools can easily be extended for future instruments and used for other projects.