INFO: Internet Explorer Support of Netscape Plug-in (166694)

SUMMARY

Although Internet Explorer supports 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 the NPN_PostURLNotify and NPN_GetURLNotify functions.
Internet Explorer (16-bit) does not support the NPN_PostURL function.
Internet Explorer does not support the NP_ASFILEONLY flag on calls to the NPP_StreamAsFile function. Use the NP_ASFILE flag instead.
Internet Explorer 4.0 and 4.01 (32-bit) stops responding (crashes) if the NPN_PostURL function is called. This is fixed in Internet Explorer 4.01 Service Pack 1.
Internet Explorer does not support the Java Runtime Interface (JRI). .
All plug-ins are notified that they are 0.9 level, even though Internet Explorer does not support some 0.9 level functionality.

Plug-in developers should check the user agent string, as well as the version number. If the user agent is Internet Explorer, do not make calls to either NPN_PostURLNotify or NPN_GetURLNotify.

REFERENCES

For additional information about Internet Explorer 5.5 Service Pack 2 and later that do not support Netscape-style plug-ins, click the article number below to view the article in the Microsoft Knowledge Base:

303401 Netscape-Style Plug-ins Do Not Work After Upgrading Internet Explorer

For more information on using user agent strings, see the following MSDN Online Web Workshop article:

"Sniffing For Browsers, Virtual Machines, and Operating Systems"
http://msdn.microsoft.com/workshop/management/sniffing.asp

For more information, see the MSDN Online Web Workshop site:

http://msdn.microsoft.com/workshop/

The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.