Hop (software)

Hop is a Lisp-like programming language by Manuel Serrano for web 2.0 and also the name of the web broker (server and proxy) that implements this language. It is written in Bigloo Scheme. It is a project funded by INRIA.
Language design.
Hop is a stratified language, which means that a single program file contains instructions for both the server and the client. The server executes CPU demanding computations and operations that require system privileges for accessing files or other resources. The clients (of which there may be many such as browsers, cell phones, etc.) are dedicated to executing actions related to the programming of the graphical user interfaces.
(define-service (server-date) ;1
 (current-date)) ;2
(<HTML> ;4
 (<BUTTON> ;5
 :onclick ~(with-hop ($server-date) ;6
 (lambda (h) (alert h))) ;7
 "Server time")) ;8
The code snippet above illustrates a few concepts.
Issues.
Given its recent introduction, Hop currently exhibits a number of weaknesses.