Which Programming Languages How to Use on Android Dalvik

Which programming languages can I use on Android Dalvik?

At launch, Java was the only officially supported programming language for building distributable third-party Android software.
Android Native Development Kit (Android NDK) which will allow developers to build Android software components with C and C++.
In addition to delivering support for native code, Google is also extending Android to support popular dynamic scripting languages. Earlier this month, Google launched the Android Scripting Environment (ASE) which allows third-party developers to build simple Android applications with perl, JRuby, Python, LUA and BeanShell. For having idea and usage of ASE, refer this Example link.
Scala is also supported. For having examples of Scala, refer these Example link-1 , Example link-2 , Example link-3 .
Just now i have referred one Article Here in which i found some useful information as follows:
1. programming language is Java but bridges from other languages exist (C# .net - Mono, etc).
2. can run script languages like LUA, Perl, Python, BeanShell, etc.
I have read 2nd article at Google Releases 'Simple' Android Programming Language . For example of this, refer this .
Just now (2 Aug 2010) i have read an article which describes regarding "Frink Programming language and Calculating Tool for Android", refer this links Link-1 , Link-2
On 4-Aug-2010, i have found Regarding RenderScript. Basically, It is said to be a C-like language for high performance graphics programming, which helps you easily write efficient Visual effects and animations in your Android Applications. Its not released yet as it isn't finished.

Which programming languages can be used to develop in Android?

At launch, Java was the only officially supported programming language for building distributable third-party Android software.
Android Native Development Kit (Android NDK) which will allow developers to build Android software components with C and C++.
In addition to delivering support for native code, Google is also extending Android to support popular dynamic scripting languages. Earlier this month, Google launched the Android Scripting Environment (ASE) which allows third-party developers to build simple Android applications with perl, JRuby, Python, LUA and BeanShell. For having idea and usage of ASE, refer this Example link.
Scala is also supported. For having examples of Scala, refer these Example link-1 , Example link-2 , Example link-3 .
Just now i have referred one Article Here in which i found some useful information as follows:
1. programming language is Java but bridges from other languages exist (C# .net - Mono, etc).
2. can run script languages like LUA, Perl, Python, BeanShell, etc.
I have read 2nd article at Google Releases 'Simple' Android Programming Language . For example of this, refer this .
Just now (2 Aug 2010) i have read an article which describes regarding "Frink Programming language and Calculating Tool for Android", refer this links Link-1 , Link-2
On 4-Aug-2010, i have found Regarding RenderScript. Basically, It is said to be a C-like language for high performance graphics programming, which helps you easily write efficient Visual effects and animations in your Android Applications. Its not released yet as it isn't finished.

a compiler that compiles down to dalvik bytecode?

It seems that the only way to write an android app is by using java

You are welcome to use C/C++ as well.

Apps run in a virtual machine called the "dalvik virtual machine"

Only on Android 4.4 and older. Newer devices use a new runtime environment called ART.

then wouldn't it be possible to create a C/C++ (or any other compiled language for that matter) compiler that can compile down to dalvik bytecode?

Can you craft other languages that compile to Dalvik bytecode? Sure. Can you compile some existing language to Dalvik bytecode? Only if the language features of that language can be implemented (reasonably) in Dalvik bytecode.

Android Adverse To Dynamic Languages

Dan Bornstein gave a presentation on Dalvik at Google I/O. It's worth watching to learn about the system in general, including the constraints you care about. The specific issue of non-Java languages compiled into Java bytecode comes up during the Q&A.

Remco van 't Veer has a github project where he's patched Clojure to work on Android. Tim Riddell has written a tutorial on how to use it.

As mentioned here by @sean, there is sometimes a bigger problem than just performance. Dan Bornstein discusses it when asked about Jython, at ~54:00 in video. There is currently no support for dynamic languages which generate bytecode on-the-fly, (because the bytecode translation is not available at runtime).

What is Smali Code Android

When you create an application code, the apk file contains a .dex file, which contains binary Dalvik bytecode. This is the format that the platform actually understands. However, it's not easy to read or modify binary code, so there are tools out there to convert to and from a human readable representation. The most common human readable format is known as Smali. This is essentially the same as the dissembler you mentioned.

For example, say you have Java code that does something like

int x = 42

Assuming this is the first variable, then the dex code for the method will most likely contain the hexadecimal sequence

13 00 2A 00

If you run baksmali on it, you'd get a text file containing the line

const/16 v0, 42

Which is obviously a lot more readable then the binary code. But the platform doesn't know anything about smali, it's just a tool to make it easier to work with the bytecode.

Dalvik and ART both take .dex files containing dalvik bytecode. It's completely transparent to the application developer, the only difference is what happens behind the scenes when the application is installed and run.

What is ART and DART in Android

ART

ART is the new Android Runtime. The idea is to replace the Dalvik Virtual Machine with an ahead-of-time on-device compiler suite called dex2oat and a new runtime environment for apps. So if you install an application, it is first compiled to native code by using one of the dex2oat compilers, for example Quick(default in 5.0, 5.1) or Optimizing (default from 6.0), and stored in a so called oat file, which is an ELF shared object.
When the app is executed, the runtime loads the content of the oat file into a preinitialized app process.
The advantage of AOT compilation is, that you can do state-of-the-art optimizations because it does not execute at runtime. So we get faster apps but slower installation time.

DART

As you gave the link to the Android Dev page, I assume you are NOT talking about the DART language but about the Dalvik Runtime.

Dalvik is Android's bytecode interpreter (and JIT compiler) that used to interpret and optimize app code on the fly while executing it. So compared to a AOT compilation, the amount of optimization that can be done is restricted by the fact that longer optimization time slows down the actual execution of the application. Dalvik is superseded by ART in Android 5. Still, apps' code is stored as dex files which are the input format for the ART compilers. Also, for debugging purposes and for devices with low persistens memory, the interpreter is still around, even though it is not default and it might be a lighter version.

Android: Java, C or C++?

The article you link to has good information. It also links to http://developer.android.com/sdk/ndk/overview.html which says:

The NDK will not benefit most applications. As a developer, you need
to balance its benefits against its drawbacks; notably, using native
code does not result in an automatic performance increase, but always
increases application complexity. In general, you should only use
native code if it is essential to your application, not just because
you prefer to program in C/C++.

Typical good candidates for the NDK are self-contained, CPU-intensive
operations that don't allocate much memory, such as signal processing,
physics simulation, and so on. Simply re-coding a method to run in C
usually does not result in a large performance increase. When
examining whether or not you should develop in native code, think
about your requirements and see if the Android framework APIs provide
the functionality that you need. The NDK can, however, can be an
effective way to reuse a large corpus of existing C/C++ code.