The top three ecommerce platforms are all Java based (hybris, Oracle ATG and IBM Websphere) and there are a ton of "tier 2" platforms that are cover the .net and PHP stacks. The tier 1 systems will cost you a significant amount of money to get up and running though (over a million $ is not uncommon).

If you only know of the PHP platforms then I guess you don't play at any significant level in the industry (like most people on HN).

This is actually a candidate for shit hn says.