The User Guides for the Huygens Software in PDF can be currently found at Huygens User Guides* (login required).
There is also an on-line html version of the Huygens Core Programmer Guide. You can also search for Tcl Huygens commands in the → On Line Tools.
(See also the Alternative Covers!)
Image in the Huygens Manuals covers is the Evans Macrophage.
This article is taken from the SVI-wiki, a support base that also you can edit.