MetaTrader 4, also known as MT4, is an electronic trading platform widely used by online retail foreign exchange speculative traders. It was developed by MetaQuotes Software and released in 2005. The software is licensed to foreign exchange brokers who provide the software to their clients. The software consists of both a client and server component. The server component is run by the broker and the client software is provided to the broker's customers, who use it to see live streaming prices and charts, to place orders, and to manage their accounts.
The client is a Microsoft Windows-based application that became popular mainly due to the ability for end users to write their own trading scripts and robots that could automate trading. In 2010, MetaQuotes released a successor, MetaTrader 5. However, uptake was slow and as of April 2013 most brokers still used MT4. While there is no official MetaTrader 4 version available for Mac OS, some brokers provide their own custom developed MT4 variants for Mac OS.
MetaTrader 5 is an institutional multi-asset platform offering outstanding trading possibilities and technical analysis tools, as well as enabling the use of automated trading systems (trading robots) and copy trading. MetaTrader 5 is an all-in-one platform for trading Forex, Stocks and Futures.
The two major differences have already been covered, but there are a number of others worth mentioning within any MT4 and MT5 comparison. Metatrader 5 uses a programming language called MQL5 as opposed to the MQL4 used by Metatrader 4. The exciting thing about MQL5 is that it allows 'black box' programming which, in a nutshell, means that it is easier to program and so will logically be a better framework for users and developers of trading robots and other expert advisors. However, MetaQuotes expanded this capability into MQL4 in 2014, so it is not a difference between the platforms any more, although there is a likelihood that if the language is upgraded at some time in the future, MetaQuotes will not extend any upgrades into MQL4 as well as MQL5 It should be noted that there is no backwards compatibility. Programs written for Metatrader 4 cannot run on Metatrader 5. This can be a serious drawback for traders who were wishing to 'upgrade', and is a key reason why such a change shouldn't be seen as an upgrade. It is true that Metatrader 5 retains two key programming-related advantages over Metatrader 4. Firstly, its back testing functions where you can test programmed trading strategies execute at a much faster speed, which is a feature that can save you a lot of time if you are the kind of trader who needs to run a large number of back tests. It also allows simultaneous multi-currency pair back testing. Together this can speed up back testing procedures immeasurably.