Acknowledgements

We are thankful to all those users who, over the years, have reported problems, suggested improvements, or provided encouragement.

Jurgen Doreleijers, Sander Nabuurs, Chris Spronk and the partners in the EU-sponsored NMRQUAL project have contributed to the NMR specific aspects of WHAT_CHECK.

The partners in the EU-sponsored CRITQUAL project have contributed to the X-ray specific aspects of WHAT_CHECK.

We thank the EU for funding this project in the fourth and the fifth framework.

Recently we received funding from NBIC:
"This work was part of the BioRange programme of the Netherlands Bioinformatics Centre (NBIC), which is supported by a BSIK grant through the Netherlands Genomics Initiative (NGI)". Robbie Joosten's PhD position will be funded from this money; he will work on the interface betwee WHAT_CHECK and refinement.