TOPCONS is a program for predicting the topology of an alpha-helical membrane protein based on its amino acid sequence. The prediction is a consensus from five different topology prediction algorithms which are used as input for the TOPCONS hidden Markov model. This gives a consensus prediction for the protein, along with a reliability score based on the agreement of the included methods across the sequence. In addition, ZPRED is used to predict the Z-coordinate of each amino acid. TOPCONS functions are available programmatically via SOAP calls.