Arduino has emerged as one of the
prime success stories of the open-hardware movement. In recent years, the
company has shifted its focus toward Internet of Things (IoT)
applications. As part of this transformation, it has completely redesigned
its open-source integrated development environment (IDE), adding a more
professional feature set for its hobbyist target audience. If you have
experimented with Arduino in the past, but have lost track of its
progress, now might be a good time to give it another try.

Source: LWN.net – [$] Arduino: open source for microcontroller boards