new EJS
EJS.startTag; // '<%';
EJS.endTag; // '%>';

Terms:
Unclosed logical blocks:
	if, else, for, ... blocks; if( ??? ) { ... }
Unclosed functional blocks:
	someFunction( ... )

For code examples the default <% and %> start and end tags are used, however these can be customized at compile time.

Full templates have the following intro code added:
function() { var _buf = [];
And the following outro code added:
return _buf.join(''); };

Compiled syntax translations.
-- Simple code blocks
abc<% fn(); %>123
_buf.push( 'abc' ); fn(); _buf.push( '123' );

-- Echoing code blocks
abc<%= fn(); %>123
_buf.push( 'abc' ); _buf.push( fn() ); _buf.push( '123' );

-- Echoing code blocks with filters
abc<%h= fn(); %>123
_buf.push( 'abc' ); _buf.push( EJS.filters['h']( fn() ) ); _buf.push( '123' );

-- Unclosed logical blocks
abc<% if( true ) { %>xyz<% } %>123
_buf.push( 'abc' ); if( true ) { _buf.push( 'xyz' ); } _buf.push( '123' );

-- Unclosed functional blocks
abc<% fn( %>xyz<% ); %>123
_buf.push( 'abc' ); fn( function() { _buf.push( 'xyz' ); } ); _buf.push( '123' );

-- Echoing unclosed functional blocks
abc<%= fn( %>xyz<% ); %>123
_buf.push( 'abc' ); _buf.push( fn( function() { var _buf = []; _buf.push( 'xyz' ); return _buf; } ) ); _buf.push( '123' );


Logical blocks may not be used directly in echoed syntax. ie: you can't do this: abc<%= if( true ) { foo(); } %>

%>'s are dominant over //'s, if a // ... %> is found where a %> follows a // on the same line then all text from the // to the %> is discarded
/*'s are dominant over %>'s, if a /* is found in open code the comment runs on until the next */ and discarded. So <% /* %> */ %> will discard the %> in the middle instead of considering it the end of the code mode.
Strings are dominant over %>'s, just like a /* a %> inside of a string will not be considered the end of a block.
Markup blocks inside of object and array blocks are treated like "Echoing unclosed functional blocks"
Ending ;'s in code are stripped and EJS adds it's own in the proper place, see "Echoing code blocks" to see why this is necessary.