- Zoiper - Still as good as an option as it was at the time of the post. The interface seems to have remained unchanged but all of the functionality of the free version is still there. I'd still recommend Zoiper as a softphone and it's the softphone app I use on my cell when I need it for work purposes.
- 3CX - You can still find the free version of 3CX via their website, but it's been an end-of-life product for a few years and will not see any further updates. Their newer version of the 3CX softphone only works with their phone system, ie. you can't use it for any old Asterisk based contact center ACD, it must be used with their 3CX phone system. With that in mind, I really cannot comment on whether or not their newest version of their softphone is any good at all as I haven't used it. The free version is still ok, but I've mainly stopped using it.
- X-Lite - I just fired this up now for the purpose of this post. There's no denying the aesthetic appeal of X-Lite over Zoiper and 3CX, but it's so incredibly resource heavy that it's really impossible to recommend or even use on a day-to-day basis. The only reason I have it installed on my work machine is as a last resort softphone option, and that hardly ever happens. It's not any lighter to run that it used to be either. Just for reference, X-Lite idling is using 86.6MB of memory, compared to 4.7MB and 20.7MB for Zoiper and 3CX respectively.
Since the last post, I've fiddled a bit with some other softphones. While Zoiper used to be my primary option, I'm now using MicroSIP as my main softphone. There's nothing to brag about with respect to how it looks, but it's quite simple to setup and to use and it's even less resource heavy that Zoiper, checking in at 2.7MB compared to 4.7MB. In my experience, agent workstations in the contact center ACD are typically underpowered, so using an application that is exceptionally lightweight is highly desirable. I haven't really used my MicroSIP softphone to do much more than make and take calls, but that's all I need my softphone to do, and this one does that with ease. I would certainly recommend this product if you are looking for a free softphone.