Littlefoot is a custom programming language built by ROLI to allow creators to write and use scripts – or Littlefoot apps – that control the behavior of BLOCKS. Littlefoot is a C-like language designed to have a very small footprint, hence its name. Littlefoot apps primarily live on the creator’s desktop, and ROLI Dashboard can upload them to connected Blocks.
Note that when a Block is connected to the BLOCKS API – for example when using NOISE or the Max BLOCKS Package – the Block will bypass any Littlefoot app running. As soon as a Block disconnects from the API, it will revert back to the Littlefoot app currently saved on the Block.
And for more information on the origins of Littlefoot, check out Jules Storer's 2016 Audio Developers Conference keynote presentation, entitled "Only an idiot would write a new C-like language in 2016":