only mt4?

[Thintwit1954]

Hi, I wanted to ask one thing to the experienced trader, certainly more experienced than me, on several websites I read that in addition to platforms such as MetaTrader, there are also other platforms, I'd get the chance to know someone new, you know something more to regard? And a broker who uses them? Also, I read there also exist some proprietary, what does this mean? Ordinary mortals like us cannot be accessed?