The commercial application of high temperature Fischer-Tropsch (HTFT) technology is described. The types of reactor used an discussed with emphasis on the advantages of using the Sasol Advanced Synthol (SAS) reactor. A reactor replacement project at Secunda, South Africa will result in a total installed capacity of 124 000 barrel per day of products from the new SAS reactors. The preparation of the catalyst used in these reactors is described. The changes to the catalyst structure during synthesis are illustrated, making it clear that the actual catalyst consists of small carbide/magnetite particles embedded in a continuous carbon phase. The changes in catalyst morphology which occur during synthesis are discussed with reference to the effect on the observed post sulphur poisoning behaviour. The SAS process can be considered to be a mature technology which has been applied in large-scale commercial plants. Future applications should take advantage of the considerable potential to recover chemical feedstocks from the primary Synthol products. The potential amounts of these chemical feedstocks are quantified.