> My comment said "database" and not "API" :) Sure, but it is quite common for companies offering database access to offer that via an API to query the databas

> My comment said "database" and not "API" :) Sure, but it is quite common for companies offering database access to offer that via an API to query the database on their server rather than letting customers download the whole database for local use. It thus seemed worthwhile to make it clear that MaxMind does let you download the whole database. As far as libraries go sure that's a possibility. But for people who just need a simple IP to country or IP to US state lookup and need that from a variety of languages it may be overall less annoying to make your own DB from the CSV files that just handles what you need and nothing more. I've already got libraries for sqlite, MySQL, or both for every language I use where I need to do these lookups, and almost all the applications that need these lookups are already connecting to our databases. Add an IPv4_to_Country table to that database (that they are already using) and then it just a matter of doing a "select country_code from IPv4_to_Country where ip_low <= ? and ? <= ip_high" with the two '?'s replaced with the IP address we want to lookup, probably using a DB handle they already have open. Many would find that a lot easier than adding a dependency on a 3rd party GeoIP library. Beside it being one more thing on each machine that needs periodic updating (or rather N more if you are working in N different languages on that machine), I believe that most of these libraries require you to have a copy of the download database on the local machine, so that's another thing you have to keep up to date on every server. With the "make your own simple SQL DB" approach you just have to keep an up to date download from MaxMind on the machine that builds your SQL DB. After building the SQL DB you then just have to upload it to your one network DB server (e.g., your MySQL server) and all your apps that query that DB are up to date no matter what server they are on or what language they are in. If you are building an sqlite DB for some of your apps, you do have to copy that to all the servers that contain such apps, so you don't totally escape having to do updates on those machines. If making the SQL DB were hard then maybe reducing dependencies and reducing the number of things that need updates might not be worth it, but the CSV files are organized very sensibly. The scripts to make the SQL DBs are close to trivial if you've got a decent CSV parser in the language you are writing them in.