These are the 7 blog posts written on July 21 of any year. (Nearby: July 20 and July 22.)
2019:
Set_env.py #my-code
2008:
Pre tags in comments #site
2006:
Spamlent Green is people #malware
2005:
Very small objects #art #science
Google maps pedometer #google #maps #walking
2003:
ZMatrix
2002:
Stephen Wolfram’s unfortunate ego