PHP 5.3 introduced some new functions:
- imap_gc() - Clears IMAP cache.
- imap_utf8_to_mutf7() - Encode a UTF-8 string to modified UTF-7.
- imap_mutf7_to_utf8() - Decode a modified UTF-7 string to UTF-8.
- preg_filter() - Perform a regular expression search and replace, returning only results which matched the pattern.
The following functions are now natively implemented, making them available on all operating systems which can run PHP: