8x8 is a powerful unified collaboration and virtual call center platform. The company boasts a sizable user base (40,000 businesses) and is very well-positioned. 8x8 reviews are mostly positive. However, at $50 per user per month to get most advanced features, it’s not exactly cheap. If you are looking for a free 8x8 alternative that comes with essentially the same set of features (virtual call center, CRM, unified communications) and is available both in cloud and as self-hosted software that comes with open source code access, take a look at Bitrix24.
* Please note that the information may have changed since the publication. For current prices and features please visit Bitrix24 pricing page.