Soft phone and browser pops

Hi all,

So I’ve been searching for a solution for a while and what’s left of my hair is in bad shape, so I’m hoping someone here knows what I’m looking for. I’m looking for a softphone (preferably open source and free) that can properly handle asterisk’s sendURL command. It will need to work on both Windows and Linux. In a perfect world we’d like to integrate it into our CRM software, but that can wait. Sip would be best, IAX would be ok. Does anyone have any experience w/ a softphone that would fit these requirements?

Many thanks!