Aleks streaming mode installs additional java code in the browser's cache, not in the Java directory. The first time aleks.com/plugin is run (the address will read www.aleks.com afterwards - don't panic), it takes several minutes for the software to download. After that, when aleks.com/plugin is run, which is a must, then only one or two seconds is used.
Streaming is used when old Macs or PC's that have non-current software or are locked by administrators to prevent installation of software, such as ALEKS, are used.
For example, on an iMac that had no administrator access and two years since the last update, the ALEKS stream worked with the old Java and old Safari browser. This is a big win.
This feature has a secret benefit, if the three hour trial mode of ALEKS is used on non-ALEKS computers, then many students can be tested without IT support. This saves money.