Well today emerald team has announced their final release and discontinuation of their viewer, There will likely eventually be a fork of this viewer but users may be looking to continue the use of its features through another viewer, I heard someone recommend Kirstens viewer in its place, I tried this and was displeased with Kirstens as an alternative you can find the announcement regarding the discontinuation here:
anyhow Emerald development ceases with this final release, there will likely be other viewers that are built from emerald and a fork of such, but nonesuch have registered for the TPV List yet however there is a viewer inclusive of some features from emerald which can be seen here:
I've used Imprudence before and tried it and hated the abysmal performance, tried it using the latest Release Candidate, Loved it. The performance of the latest release candidate on my system(Imprudence 1.3.0 RC2) was excellent and it can be found here:
Also its on the third party viewer directory which means it has been approved by Linden Labs and has not done anything to lose that approval which can be found here:
If performance with this viewer however is an issue for you they do provide a solution, as their not licensed to distribute llkdu libraries they use the Slower OpenJPEG libraries instead, however I have not tried this as of yet but will be doing so soon, but they say you can use the LLKDU library yourself you will just need to install and copy it, they mention the solution here:
Many emerald users are hooked on Emerald for The built in AO that does not impose on SL's scripting Engine where as scripted AO's need to constantly check the avatar state in the sim thus creating lag, or are hooked on the math features for build or the breast physics all that such can be used in Imprudence
You can find information on building using math expressions here:
as for the AO yes its there too, mind you it doesn't have the latest check-box that allows you to stop the timer within it, but that's fine cause you can just set the timer high to stop cycling the AO can be found under "View > Animation ovetrider" but I cant help but notice the Hotkey listed for it is the same as the Object occlusion hotkey under the advanced menu.
If You liked Emeralds version of "show look at" and how it named the camera points so you could get an idea who may be camming into your skybox the same modification for "show look at" exists within imprudence it just hasn't been moved, it exists in its old location in the advanced menu "advanced > character > show look at". it does pop up a warning that you shouldn't rely on this for privacy, there's several reasons for this, viewers don't always accurately receive this information and sometimes can show different look at points between viewers(a net packet gets dropped and someone that gave you cam focus hours ago may appear to still be doing so), viewers can disable broadcasting of this(imprudence can too but disables this if you do) and also people can always cam in from other sources.
Also there is the breast physics, mind you I did not find options related to this in imprudence unlike emerald(not saying their not there, but the imprudence team intended it be a subtle thing it appears) however the options still exist within the debug menu under advanced and their settings are under the entries:
the settings seem to be the same as emeralds and follow emeralds defaults so if you adjusted this you can copy the debug entries here and make it the same I guess, I'm not going to mess with the settings myself though.
Extended Edit: well another worth mention feature I forgot to mention that was mentioned to me by a friend is the radar feature, both imprudence and emerald have this but use different implementation. emeralds radar has a longer range, the one in imprudence has a range setting and is built into the minimap with a drop down arrow marker, it however is limited to 512m where as the emerald one apparently had a much longer range than that but still if you need a radar both viewers have it built in, just the emerald one is superior, however, it is available in imprudence nonetheless, another worth mention feature I forgot to mention is imprudence does have an implementation of area search which allows you to search the area much the way emerald does with its area search feature,you can search an area by name, by owner, by group or by description, Both viewers have this however I noticed when using this in emerald I would get a drastic frame rate drop, imprudence this feature seems to run smoothly, whatever the case, its good for finding parcels that have implemented zf redzone which should be avoided like the plague, something I think would make a cool edition to this feature though, is the ability to search by object creator, but still nonetheless a greatly useful feature that exists in both viewers