Word alignment (WA) between a pair of sentences in the same or different languages is a key component of many natural language processing tasks. It is commonly used for identifying the translation relationships between words and phrases in parallel sentences from two different languages. WA-Continuum is a tool designed for the visualisation of WAs. It was initially built to aid research studying WAs and ways to improve them. The tool relies on the automated mark-up of WAs, as typically produced by WA tools. Different from most previous work, it presents the alignment information graphically in a WA matrix that can be easily understood by users, as opposed to text connected by lines. The key features of the tool are the ability to visualise WA matrices for multiple parallel aligned sentences simultaneously in a single place, coupled with powerful search and selection components to find and inspect particular sentences as required.