Many customers running legacy applications are also running legacy hardware, and old PCs tend to be memory constrained.
To help in cases where PCs are under severe memory pressure, Ion has a “Limited Profile” option, which makes many of Ion’s features available but without the overhead of additional processes running on the system (and therefore not taking up extra memory).
The tradeoff is that only a subset of Ion’s features are available to the Limited Profile. However, if the limited subset of available features helps customers get their web applications working with Ion, it can be a useful solution to the memory problem.
I’ve posted this KB article at our support site that details which features are and are not available to Limited Profiles, but here are the notable features NOT available to Limited Profiles, with a brief discussion of what each means:
Custom DEP/NX settings. Because Ion is not running in a separate process, Limited Profiles must adhere to the DEP/NX setting used by the host browser (IE8 or IE9).
Custom ActiveX control settings. Web applications running the Limited Profile cannot load custom ActiveX controls (including Java). The default versions of all ActiveX controls loaded by the host browser (IE8 or IE9) will load in a Limited Profile.
Custom Registry settings. Limited Profiles run without the Ion sandbox, so no custom registry settings (including Feature Control Keys) can be set. All Regsitry values will be read normally out of the user’s registry.
Note that there are a few more features not available to Limited Profiles that are detailed in the KB article that are not listed here.
However, there are still quite a few features that are available to Limited Profiles, and they may be enough to get your web-based application running. A short list of features that can still be used by Limited Profiles include (but is not limited to): custom User Agent string settings, string replacement, script injection and content override.
If your PC environment is running with severe memory constraints and the list of features available to you suffices to get your legacy web applications running inside IE8 or IE9, then the Limited Profile may be just what you need.