title: What is a compiler toolchain?
body: <p>From the latest <a href="https://www.reddit.com/r/GlobalOffensive/" rel="nofollow noreferrer">CS:GO</a> update, a valve dev commented this on the <a href="https://www.reddit.com/r/GlobalOffensive/comments/6ao86u/counterstrike_global_offensive_prerelease_update/" rel="nofollow noreferrer">reddit post</a>:</p>
  <blockquote>
  <p>We are upgrading the compiler toolchain we use to build CS:GO. This
  pre-release branch has CS:GO built with the new toolchain. We are
  releasing it as a pre-release branch to allow for testing ahead of it
  being used in the next update.</p>
  <p>There are no functional changes expected, though the new compiler
  toolchain may yield a small performance boost.</p>
  </blockquote>
  <p>Can anyone explain what a compiler toolchain is?</p>