The mimimum requirement for HyperLens is a working JAVA 1.1 installation. If you don't already have one, please see the JAVA FAQ for further information.
The viewer available for download is packaged as a JAVA Archive (jar) file, and can be run using
java -cp HyperLens.jar HyperLensViewer http://www.webthing.com/software/hyperlens/front
Note - for controlled (e.g. CDROM) distributions, the threaded version of HyperLens runs faster and more smoothly. It is not publicly available here because it causes some Web browsers to crash.