Symphony's chat tool is a Slack competitor where customers can control the keys, including via HSM. On the surface it is similar to what this news is announcing Slack added to its own tool:

https://symphony.com/product/messaging-and-productivity

You're definitely confusing with Symfony, the PHP framework. As others pointed out, Symphony is a Slack competitor.

I would still say Symphony’s target is Bloomberg. Despite Symphony’s good progress so far, Bloomberg are still far ahead in market share and their network is a great moat which makes it very hard to substitute, also given that onboarding new platforms across financial firms is a huge challenge even when you aren’t pushing against network effects benefiting your main competitor.

Can you clarify? They both offer chatrooms and depending on your definition of webapp framework they both are as well (external app integration, bots...).

Can_Not was probably thinking about Symfony [1].

[1]: https://symfony.com/