User-agent: *
Disallow: 


RewriteCond %{REQUEST_URI} !^/robots.txt$ [NC] 
RewriteCond %{HTTP_USER_AGENT} ^.*viswoo.* 
RewriteCond %{HTTP_USER_AGENT} ^.*penthesilea.*
RewriteRule ^.*$ - [F,L]

User-agent: Heritrix
Disallow: /

User-agent: penthesilea
Disallow: /