Searching for questions tagged with PHP or MySQL or JavaScript or
4953
Search [tag1] OR [tag2]
124446
Where and How should a Stack Exchange user ask questions regarding finding APIs for a specific purpose?
39711
Link up the excellent search engine that gives "Questions that may already have an answer" with the search box
89948
Include tags in answers entries on search results
33320
Filtering "hot" questions
69062
Please add a tag search functionality to Careers
93665
Is there a way to see questions with a certain tag from all Stack Exchange sites?
157035
Show Google results along with related questions
30978
Parse question links from other SE sites
87240
Search by multiple tags
158277
How to search unanswered questions
117963
Select and Display 'Suggested Tags' for All Posts Based on Related Questions (or other logic)
35575
Automatic tag suggestions
92092
How to search for questions and answers between two users?
26079
Email notifications for new questions matching specific tags
48663
Possible Tags similar to "Related Questions" under Title
105977
Can I search my comments using some keyword(s)?