Own Implementation
Split text into tokens
Store tokens in a table, uniquely - with frequency
Store object / word location in a table, next/prev word, order
mysql> select * from ezsearch_word order by word limit 250, 4;
+------+--------------+--------------+
| id | object_count | word |
+------+--------------+--------------+
| 1761 | 1 | associations |
| 2191 | 1 | assurance |
| 349 | 37 | at |
+------+--------------+--------------+
mysql> select word_id, word from ezsearch_object_word_link wl, ezsearch_word w
where wl.word_id = w.id and contentobject_id = 145 order by placement limit 4;
+---------+--------+
| word_id | word |
+---------+--------+
| 1576 | puts |
| 926 | europe |
| 349 | at |
+---------+--------+