The get_browser () function currently can only use a single browscap.ini, as specified in php.ini. Therefore (to my knowledge) if the browscap.ini is changed, the server (I'm using Apache) must be restarted before the changes filter through to PHP. In my situation (and probably many others), I don't own or have rights to the server, and the owners are unwilling to restart the server (I'm developing a customized browscap, and I make changes frequently).

What I suggest (I don't have enough knowledge of C, or I'd do it myself) is overloading the get browser function,
from: object get_browser ([string user_agent])
to: object get_browser ([string user_agent], [string browscap_file])

When the function is called, it loads the browscap_file to memory and uses that instead of the global file. This would also be useful where multiple sites are hosted on the same server, but the sites wish to use different browscap files.