Tools

Bear Mountain Software
BMS's TOPPER network and email management tool performs real-time monitoring, alerting, and reporting for NT and Unix-based systems.
http://www.bearmtnsw.com

ByteSphere's OiDView
A modular, expert system for SNMP agent analysis in details.
http://www.oidview.com/oidview.html

CMU SNMP Library
The CMU SNMP library provides developers with a set of core functions.
http://www.net.cmu.edu/groups/netdev/software.html

Conformance Tool for SNMP network
This site has postscript files which gives the description on the conformance tool for SNMP Network. Conformance tool detects a message sent from the SNMP manager to the agent and checks it for all the required fields in it. It warns the manager in case there is an error. [Freeware]
http://www.geocities.com/lezzden/project.htm

Fusion SNMP - v1, v2, and V3 Source Code
Provides a complete protocol stack and run-time environment required to support an SNMP agent within an embedded system.
http://www.dspos.com/DSPOSWeb/network_mgmt/fusion_snmp.htm

Future SNMPv2c
Complete implementation of the bi-lingual agent from SNMPv1 and SNMPv2c network management protocols.
http://www.futsoft.com/snmp.htm

Snmp Source
Developer toolkit for quick development of SNMP management applications. .net-library for building cross-platform, real-time applications to monitor network performance. For SNMPv1, SNMPv2c, and SNMPv3.
http://www.snmpsource.com

SNMPv1,v2c,v3 java libraries
The iReasoning SNMP library provides a high performance, cross platform Java API for building network management applications based on SNMP. All SNMP versions (SNMPv1, SNMPv2c and SNMPv3) are fully supported. It is written in Java, and has been designed from the ground up.
http://www.ireasoning.com