Using the website is very easy; simply use your web browser to connect to: software.caltech.edu
To download software, you will need to log in with your access.caltech account. If you do not have an access.caltech account, click here for instructions on obtaining one.
Most of the software on the website is free of charge to members of the Caltech community. There are a few packages that require a fee (for example: AutoCad, Personal TeX, Adobe Photoshop); these require a valid PTA number to obtain. The software download service is only available from computers connected to the Caltech network.
The software.caltech.edu web site is run by IMSS in conjunction with Kivuto Solutions. While the software packages you download are physically stored on servers housed at Caltech, the web pages that allow access are hosted off-campus (so don't be alarmed if it appears your browser is connecting to a URL not in the caltech.edu domain). See the screenshots below:
Caltech Software Webstore (hosted by Kivuto):