INFO: Internet Explorer's Netscape Plug In Support

ID: Q166694

The information in this article applies to:

Microsoft Internet Explorer (Programming), versions 3.01, 3.02, 4.0,

4.01

SUMMARY

While Internet Explorer (IE) does support Netscape Plug-ins, there are some limitations to this support. Below is a list of several known issues:

Internet Explorer does not support the type= attribute for plug-in instantiation in Internet Explorer 3.x.
Internet Explorer does not support NPN_PostURLNotify and NPN_GetURLNotify.
Internet Explorer (16 bit) does not support NPN_PostURL.
Internet Explorer does not support the NP_ASFILEONLY flag on calls to NPP_StreamAsFile(). Use NP_ASFILE instead.
Internet Explorer 4.0 and 4.01 (32 bit) will crash if NPN_PostUrl() is called.
Internet Explorer does not support JRI.
All plug-ins are notified that they are 0.9 level even though IE does not support some functionality.

If plug-in vendors check only the version number, they should also check the user agent string. If the user-agent is Internet Explorer, then they should not make calls through NPN_GETURLNOTIFY and NPN_POSTURLNOTIFY.

REFERENCES

For an explanation of user agent strings, search http://www.microsoft.com for "Browscap.ini".

Also information on user agent strings can be found in the HTTP specification "Hypertext Transfer Protocol -- HTTP/1.0" available at http://ds.internic.net/rfc/rfc1945.txt.

Keywords          : kbinterop kbusage msiexplore 
Version           : Win:3.01,4.0
Platform          : WINDOWS
Issue type        : kbinfo

Last Reviewed: February 19, 1998