C..7 Cheetah vs. PHPLib's Template class

PHPLib ((http://phplib.netuse.de/) is a collection of classes for various web objects (authentication, shopping cart, sessions, etc), but what we're interested in is the Template object. It's much more primitive than Smarty, and was based on an old Perl template class. In fact, one of the precursors to Cheetah was based on it too. Differences from Cheetah:

Templates consist of text with {placeholders} in braces.
Instead of a searchList, there is one flat namespace. Every variable must be assigned via the set_var method. However, you can pass this method an array (dictionary) of several variables at once.
You cannot embed lookups or calculations into the template. Every placeholder must be an exact variable name.
There are no directives. You must do all display logic (if, for, etc) in the calling routine.
There is, however, a ``block'' construct. A block is a portion of text between the comment markers  ... <!-- END blockName>. The set_block method extracts this text into a namespace variable and puts a placeholder referring to it in the template. This has a few parallels with Cheetah's #block directive but is overall quite different.
To do the equivalent of #if, extract the block. Then if true, do nothing. If false, assign the empty string to the namespace variable.
To do the equivalent of #for, extract the block. Set any namespace variables needed inside the loop. To parse one iteration, use the parse method to fill the block variable (a mini-template) into another namespace variable, appending to it. Refresh the namespace variables needed inside the loop and parse again; repeat for each iteration. You'll end up with a mini-result that will be plugged into the main template's placeholder.
To read a template definition from a file, use the set_file method. This places the file's content in a namespace variable. To read a template definition from a string, assign it to a namespace variable.
Thus, for complicated templates, you are doing a lot of recursive block filling and file reading and parsing mini-templates all into one flat namespace as you finally build up values for the main template. In Cheetah, all this display logic can be embedded into the template using directives, calling out to Python methods for the more complicated tasks.
Although you can nest blocks in the template, it becomes tedious and arguably hard to read, because all blocks have identical syntax. Unless you choose your block names carefully and put comments around them, it's hard to tell which blocks are if-blocks and which are for-blocks, or what their nesting order is.
PHPLib templates do not have caching, output filters, etc.