'vmtouch is a tool for learning about and controlling the file system cache of unix and unix-like systems. It is BSD licensed.'

as seen in their "Instagram Engineering" post

very interesting; modern multicore x86 architectures use a NUMA memory architecture, which can cause a dip into swap, even when there appears to be plenty of free RAM available

'SoftReferences are the cheap, crappy caching mechanism [...] perfect for when you'd like your cache to be cleared at random times and in random order.'

'an online compiler/interpreter, and a simple collaboration tool. It's a pastebin that executes code for you. You paste your code, and codepad runs it and gives you a short URL you can use to share it.' supports C, C++, D, Haskell, Lua, OCaml, PHP, Perl, Python, Ruby, Scheme, and Tcl code; isolated by a geordi-based supervisor, in turn running inside a firewalled virt, in turn running inside a firewalled dom0. nice work!