Choosing which programming languages to use for the IoT application development project can be as big a decision as choosing an IoT hardware platform. The options are many and when choosing technologies for programming IoT apps it's recommended that companies evaluate the existing pool of available developers, their cost per hour as well as the general size of developer community, quality of support and best practices / use cases applicable to the particular industry / niche the company is working in.
Now let's see what each language can bring to the table when it comes to the IoT app development.
Originally, C was developed to program telephone switches and is now used on nearly every advanced embedded system that exists. Also, C is a basic language that most of available SDKs are based on. Most of professional programmers have at least some knowledge of C, so the learning curve can be shortened as a result of the available body of knowledge. C is a procedural compiled language that doesn't come with a built-in GUI; despite this, it still appears to be a great fit for any IoT dev project.
C++ was developed as a C pre-processor and keeps the spare nature of C while adding classes, objects and data abstraction. It's one of the most popular languages used for coding IoT apps for Linux systems.
Java is an object-oriented language that's portable and almost independent from hardware dependencies. Java has a very vast pool of developers and is taught as a primary language in hundreds of computer science courses and degree programs, so it's one of the most profitable languages to use from an economic standpoint: investments in Java can pay off very well across many different platforms.
Prior to choosing Java, make sure your chosen IoT hardware platform supports Java and the available hardware support libraries have all the control functions you may need.
Having become one of the "go-to" languages in web development, Python is gradually spreading to the embedded development and the IoT space. It is a very flexible interpreted language that's either submitted to a run-time compiler or is run through one of several pre-compilers to distribute a compact and executable code.
In Python, readable code and elegant syntax are what matters the most. It's perfectly suited for building applications that take data, convert it into any sort of a database format and draw upon the tables for control information.
Go is superior to C for particular types of embedded programming and adds explicit types (e.g. hash table type) to facilitate data gathering from and sending to separate actuators and sensors. Go supports concurrent input, output, and processing on many different channels and, when used correctly, it enables the coordination of a whole wealth of sensors and actuators. However, if a programmer isn't careful, a system can behave unpredictably because of the lack of coordination.
One issue with Go is that it doesn't automatically share data between different channel data structures, which results in a condition that's called a "race condition", i.e. a runaway situation in which a system loses control because of many conflicting processes.
Being an open-source and rapidly evolving language, Mozilla's Rust shares some of the Go properties and helps solve one of the major issues with Go. It includes functions that eliminate race conditions and is, thus, a much less risky language for building IoT apps than Go.
If your IoT app spec requires parallel processing, Parasail is the language to consider. Parasail is a compiled and object-oriented language that allows for programming with syntax that looks like Java, C# and Python. So, we only recommend using Parasail on projects that have a specific need for a highly parallel embedded code.
Designed from the ground up as a small yet highly efficient embedded control language, B# runs on the embedded virtual machines (EVMs) that only take 24k of memory, i.e. much less than the overhead needed for other language packages. B# strips out features that aren't required for embedded programming and supports control functions in real time.
So, if your IoT application is going to run on embedded platforms that aren't as large and complex as RasPi, then B# should be the language of your choice.
Some IoT developers are very optimistic about Julia and its role in embedded development. Julia performs as seamlessly as C, but is 10x faster than R and Python and allows for distributed parallel execution.