> a) google chrome slows down the execution of javascript in inactive tabs, leading to trouble
> with memory management - midas pages poll at 1/sec, each poll allocates memory for processing RPC messages,
> and (until recently) allocates memory for new DOM objects to update the web page - but the garbage collector
> gets slowed down and does not keep up - leading to huge memory use (up to 200 Mbytes) for inactive midas pages
> that normally consume 50-ish Mbytes.

Try my latest change, which drops any update if hidden, except the alarm sound. At the moment this only works on the main "status" page.

> most midas web pages poll in two places - mhttpd_refresh() updates the current date timestamp, alarms, currently active midas.log message;
> and each page has it's own loop for updating it's own data (i.e. "alarms" page, "programs" page).

That's correct. I changed mhttpd_refresh() now and the main loop for the "status" page. If that works for everybody, we can do that also for "programs" and other pages. The code is here:

      if (document.hidden) {
         // don't update page if hidden
         setTimeout(update_page, 500);
         return;
      }

where "update_page" has to be replaced with the proper function.

Stefan