The snow watching lantern shown below is in my garden at home. A photo of it was used on the cover of the documentation for the (now obsolete) HOL88 system produced by the (now non-existent) Cambridge branch of SRI International. The currently supported descendant of HOL88 is HOL4, which is an open source project hosted at GitHub.

The original HOL88 system is available in Ubuntu Linux
(sudo apt-get install hol88).


Click here to see the participants of the first HOL users meeting.