Apologies for the cut-down site. It is a placeholder until I have time to properly replace the Drupal site that was here.
Weathermap is an open source network visualisation tool, to take data you already have and show you an overview of your network in map form.
Data is collected via plugins. Plugins are supplied for RRDtool, MRTG (RRD and old log-format), tab-delimited text files, SNMP, fping, external scripts, and Cacti-specific data. The RRDtool plugin means you have access to data from a large range of open source monitoring tools, including Cacti, Cricket, Zenoss, MRTG, Routers2, Munin, and many more. Other sources are supported via plugins or external scripts.
It also includes detailed documentation, and an interactive editor to make creating your own maps as painless as possible.
There is strong Cacti integration in particular, leveraging the Cacti plugin architecture to provide a management user interface, and access control for maps using Cacti's existing user database. Additional datasource plugins allow efficient access to data from Cacti's poller directly, and data from other Cacti plugins like THold and DSStats.
Weathermap is widely used by national and international ISPs, tier-1 carriers, internet exchanges, telcos, national academic networks, many Fortune 500 companies in finance, automotive, medical/pharma and other sectors, state and national government departments, schools and universities, and even a church.
Earlier releases are also available on github.
The development version (master branch) on github is currently halfway through a very significant refactoring/rewrite. I don't recommend it for production use! However, there is also a 0.97-maintenance branch on github, which is much more likely to be functional if you wanted to follow development.
For Cacti users, the best place for a quick question or howto is the Weathermap board on the Cacti forums.
For everyone else, and for specific bug reports, there's the Github Issues system. This makes it easier to track those issues, and whether they are resolved.
For old-school internet folks there's still a (very low traffic) mailing list, now hosted on Google Groups.
Lastly, you could e-mail me. Generally, I'd rather you used a public forum, so other people might also benefit from the work involved in solving the problem. If your question can be rewritten as either "I didn't read the manual and I want you to explain this", or "I didn't read the manual and I want you to do this for me", then we can talk about rates to do that - I have a day job, so it's not that often that I do this.
And absolutely last:
A few people have asked about donating money, or otherwise saying thanks. If you'd like to do that, there's my Amazon UK wishlist, a hardly ever updated Amazon US wishlist or cold hard cash via Paypal or Bitcoin (ask me). Typically any money is used for weathermap-related expenses, such as web-hosting, the domain name, development tools or other related things - over the years, Weathermap has 'cost' perhaps $1000 in expenses, and thousands of hours in coding and support time.