FieldAlign V3.0 is a molecular-design and 3-D structure-activity relationship (SAR) tool that generates biologically relevant molecular comparisons, which can be used to find the root causes of activity or inactivity. FieldAlign helps chemists to gain detailed understanding of the SAR of their lead molecules and to use this to design the best next synthesis. This program is a cloud-enabled application that supports parallel, distributed computing. It can be deployed both as a traditional desktop application and as a command-line application distributed onto large computing servers. FieldAlign V3.0 also introduces native support for the Mac for the first time.