PlatformIO is an open source ecosystem for IoT development 
As this quote indicates, PlatformIO provides an ecosystem which supports the development of Internet of Things (IoT) applications based on various platforms and environments.
PlatformIO supports a broad range of platforms and boards and integrates itself in Visual Studio Code as well as in Atom. For other Integrated Development Environments (IDEs), where no direct integration is available, there is the possibility to integrate PlatformIO using the Command Line Interface (CLI).
When working in the Arduino world, PlatformIO can be seen as an alternative to the Arduino IDE. However, PlatformIO is much more powerful (and in Martin's opinion also more user friendly) than the Arduino IDE. This comes both from PlatformIO itself as well as from the integration into the IDEs.
Usage at the Space
We are using PlatformIO within various IoT projects. We are trying to base any new IoT development on PlatformIO.
As example projects, please see the following:
Compared to the Arduino IDE, PlatformIO provides several advantages, some of which are:
- Integration in your favorite IDE
- Syntax highlighting
- Git integration
- Library Manager
- Manually set build-flags per project
- Automatic board and library downloads per project
We developed a seminar for PlatformIO in which you can learn the basics of PlatformIO.