IP-Blocking / Popup-Blocker / Hardening
IP filtering applications:
Peerblock
ProtoWall
Bot Revolt
HTTP filtering applications:
NoVirusThanks Website Blocker
Web Monitor
Active Wall Web Filter
Parental control:
Best Free Parental Filter
Norton Safety Minder
Windows Live Family Safety
Kidzui
K9 Web Protection
Avira Social Network Protection
Parental Control Bar
Safesquid
AOL Parental Controls
DansGuardian
Kidz CD
BlockSmart
Cloudacl Addons (FF,Ch)
GoGoStat
FoxFilter (FF,Ch)
ProCon Latte (FF)
Profanity Filter (FF, Ch)
Blocksi (Ch)
Qustodio
MinorMonitor
Kurupira Web Filter
JuniorWatch
Safe Internet for kids
Dns Angel
See also in this list: Password protect applications
IP/URL/domain blacklists:
Spy Eye Tracker
Zeus Tracker
Blocklist Manager
I-Blocklist
AlienVault
StopBadware
OpenDNS
Threat Log
DShield
More
Domain security:
Subsections follow.
1. Domain Name System (DNS):
Subsections follow.
1.1 Public DNS servers:
Norton ConnectSafe
OpenDNS
Comodo Secure DNS
DNS Advantage
ScrubIT
FoolDNS
Google DNS
Gozoom DNS
DNSresolvers
Safe DNS
CloudNS
Yandex.DNS
BA.net
OpenNIC
Verisign Public DNS
More: 1; 2
1.2. DNS server configuration:
Public DNS Server Tool
DNS Helper
ChrisPC DNS switch
QuickSetDNS
Check DNS-settings
Dns jumper
DNS Benchmark
Namebench
1.3. DNS server applications:
Unbound
DNSKong
1.4. DNS proxies:
Acrylic
1.5. DNS encryption:
Dnssec-Trigger
DNSSEC Validator (FF)
DNSSEC or not? 
DNSCrypt
SSL-DNS
2. Hosts file:
Subsections follow.
2.1. Information:
Using the Windows Hosts File for Security and Privacy
2.2. Third-party hosts files:
hpHosts
MVPS HOSTS
Hostfile
someonewhocares HOSTS
2.3. Management:
Hostsman
HostsXpert
BISS Host File Manager; download
Hostblock
BlueLifeHosts editor
PowerShell script
Hosts Block
Anti-spam:
Subsections follow.
1. Information:
How to Avoid Getting Spammed
How to Reduce Spam
Quickly Block All Future Emails From Selected Senders In Gmail
2. Spam filtering applications:
Best Free Spam Filter for the Average User
Best Free Spam Filter for Experienced Users
Spam Blockers: The Best Products for Home Use
SpamAssassin
SpamBayes
Spamihilator
SPAMfighter
Comodo Antispam
Mailwasher
BullGuard Spamfilter
POPFile
SpamPal
ASSP
Phalanx
AVS Antispam
Agnitum Spam Terrier
SafeMule
xTerminator
K9
AntispamSniper for The Bat!
SpamFence
0Spam
BitDefender 4blogs
3. Spam blacklists:
Spamhaus ; Why was my IP address listed on Spamhaus?
SpamCop Blocking List
Project Honey Pot
SURBL
SORBS
UCEPROTECT
Browser element blacklists:
SpywareBlaster
ZonedOut
Adding unwanted sites to the Internet Explorer Restricted Zone