Intercom built the modern in-app messenger - the chat bubble in the corner, paired with bots, a help center, and a shared inbox that turns live conversations into a real support operation. For product-led companies it ties marketing, onboarding, and support into one tidy surface. The trouble is the price model. Intercom has moved toward charging per resolution on top of per-seat fees, so the better its automation gets at closing conversations, the more each closed conversation can cost you - support spend that rises with your own success and is hard to predict.
The open source alternative below covers the same omnichannel ground - a website live-chat widget, email, and social channels feeding one shared agent inbox. It runs on a server you control, so support is priced by the hardware you provision rather than by how many conversations get resolved, and the full record of your customer chats stays in a database you own.