Google Wave was a pioneering collaboration platform that was unfortunately discontinued in 2012 (the product still exists as Apache Wave). Bitrix24 offers a number of advantages as Google or Apache alternative. First, there is a free cloud version. Second, Bitrix24 is available both in cloud or as self-hosted software that can be installed on your server (in which case you get access to open source code). Third, Bitrix24 offers a lot more collaboration tools that GoogleWave ever did. Finally, Bitrix24 comes with mobile apps both for Android and iOS, something that Apache Wave doesn't offer even now.
Using Bitrix24 as Google Wave alternative
* Please note that the information may have changed since the publication. For current prices and features please visit Bitrix24 pricing page.