Lua vs Erlang

One of the best features of Lua is its very well designed C API. This is very useful if you have an existing C library you need to integrate with Lua or quickly get a Lua script running on the C side of the game.

Finally Lua plays so nice with C that if you need to optimise for speed you can re-write it in C a lot easier than other languages.

The official Lua documentation is very helpful and thorough. There are also a large number of online resources or books with lots of helpful information for beginners and advanced users alike.

Lua can be built on any platform with a ANSI C compiler.

Other than that, Lua is extremely small. For example, the tarball for Lua 5.2.1 is only 245K compressed and 960K uncompressed (including documentation).

When built on Linux, the Lua interpreter built with the standard libraries takes 182K and the Lua library takes 243K.

The small size and the ability to build with a C compiler make Lua an extremely portable language that can run on a lot of different systems and computers.

Easy to learn.

Lua's performance compares very well to other languages, If performance needs to be further improved you can:

1. Implement critical parts in C
2. Use the LuaJIT compiler. The LuaJIT compiler is a drop in replacement for the stock compiler and provides significant performance improvements. From the overview page:

LuaJIT speeds can rival code written in C.

Many different game engines (e.g. Elder Scrolls series, ToME) use Lua for scripting, and it's runtime is designed for embedded use.

The Lua syntax is modeled from Modula, a language known for being a fantastic introduction to programming.

The Lua syntax also has the following key characteristics:

• Semicolon as a statement separator is optional (mostly used to resolve ambiguous cases as in a = f; (g).x(a)).
• Syntactic sugar for function calls (f'string', f"string", f[[string]], and f{table}) and method calls (obj:m()).

Due to the growing popularity, Lua has a rather large and helpful community surrounding it.

Erlang has strong roots with the telecom industry in which concurrent processes are normal. It's designed to be concurrent, to be used for distributed computing and to be scalable.

Fault tolerance means that a system has the property to continue operating even though one or more components have failed.

For Erlang systems, this means that the system is kept running even if for example a user has to drop a phone call rather than forcing everyone else to do so.

In order to achieve this, Erlang's VM gives you:

• Knowledge of when a process died and why that happened
• The ability to force processes to die together if they depend on each other and if one of them has a fault.
• A logger that logs every uncaught exception
• Nodes that can be monitored so that you find out when they go down
• The ability to restart failed processes (or groups of them)

In a real-time system it may not be possible to stop the system in order to implement code upgrades. For these cases Erlang gives you dynamic code upgrade support for free when using OTP. The mechanism is very easy to understand and works as follows:

1. Start the app
2. Edit the code
3. Recompile

That's all that is needed, the app updates with the new code while it's still running and tests are run automatically.

Erlang is made to be parallel and distributed. Because it's very easy to write code that uses multiple processor cores, it's also very easy to write applications that span multiple servers.

Erlang has been used in production for more than 20 years now. During that time it has proven itself over and over again that works great in both small startups and large-scale enterprise systems.

Erlang has been used extensively by Ericsson themselves. For example, the AXD301 ATM, which is one of Ericsson's flagships is probably the largest Erlang project ever with more than 1.1 million lines of Erlang code.

Erlang's processes have very little overhead (about 500 bytes per process). This means that a huge amount of processes can be created, even on older machines.

Erlang's processes run in a complete independent way from the OS (they aren't managed by the OS scheduler neither). This means that programs written in Erlang will run exactly the same way regardless of the operating system or platform.