Amber&#x27;s quite heavyweight and requires server-side support to do anything useful.<p>But Smalltalk&#x27;s so simple that writing your own transpiler isn&#x27;t that hard --- I have an entirely browser-side prototype in about 2kloc:<p><a href="https:&#x2F;&#x2F;github.com&#x2F;davidgiven&#x2F;stellation&#x2F;tree&#x2F;stellation5&#x2F;client" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;davidgiven&#x2F;stellation&#x2F;tree&#x2F;stellation5&#x2F;cl...</a><p>Performance is adequate, but not great. Method lookup is the dominating factor, because you need different code paths based on the type of the receiver (number, string, object...)<p>Of course, writing the libraries is the bulk of the work.