Every broker will have different charting software for you to use. The only reason a lot of people use mt4 is because its easy to use and upload indicators to. You should trial a few brokers and see what charting software is best.
Other Companies:
Trade Station - owned by the same holding company that owns the IBFX Brokerage (now can be use for Forex)
ThinkorSwim - not sure if it is proprietary as well. I know this is available through TDAmertrade.
I think the main reason most use MT4 is that it uses the standardized MQL4 language. Code can be easy modified with the right knowledge.
Not all brokers use mt4. The company i am with now , ig index, dont use it. Oanda, capital spreads and etx capital are the only other companies i have used. All of them have different charting software. Go on google and search for biggest forex brokers and then check out their websites. All of them will be promoting their charting software. There are lots of options. The charts all differ as well depending on the time zone the candlea close at.
There are many trading platforms out there: MetaTrader 4, MetaTrader 5, MultiCharts, MultiCharts .NET, cTrader, NinjaTrader 7, Ami Broker, FXCM’s platform, Oanda’s Platform, JForex, etc. Just do a little research on each and see which ones are offered by your broker and hopefully you’ll be good to go.