Template::Tiny is a reimplementation of a subset of the functionality from Template Toolkit in as few lines of code as possible.
It is intended for use in light-usage, low-memory, or low-cpu templating situations, where you may need to upgrade to the full feature set in the future, or if you want the retain the familiarity of TT-style templates.
For the subset of functionality it implements, it has fully-compatible template and stash API. All templates used with Template::Tiny should be able to be transparently upgraded to full Template Toolkit.
Unlike Template Toolkit, Template::Tiny will process templates without a compile phase (but despite this is still quicker, owing to heavy use of the Perl regular expression engine.