Usage Directions:

Step 1:
Configure an input filter (admin/config/content/alinks) to enable replacements per format and set a replacement limit.

Step 2:
Add links: /admin/content/alinks

Enter the word you want to replace in the "Word/Phrase" field.
- leave the "start" and "end" checkboxes unchecked unless you're creating a multilingual replacement.
- check the "case insensitivity" box if you want it to be case insensitive.

STEP 3:
Enter the URL for the link in the URL field.
- For external links, check the external link box and include http://.
- For internal links do not include the leading /.

Now instances of your word/phrase are turned into links.

Recommended Module:
External Link (https://drupal.org/project/extlink) adds link icons and target="_blank" to external links.