Siril is an astronomical image processing tool, able to convert, pre-process images, help aligning them automatically or manually, stack them and enhance final images. Siril is targeted to amateur astronomers having acquired images and wanting to process them in a semi-automatic way. It provides a more user-friendly interface than Iris' command line as well as more modern and powerful processing algorithms, but it is not yet as automated as DeepSkyStacker or Registax. It also provides a basic command line to access various processing functions.