A setup that configures dnsmasq and nginx to map friendly domain names (like http://ipython.p) to local ports (like http://localhost:8888).
Setup still isn't very friendly (comments, suggestions or pull requests to improve this are welcome). At a high level portmap consists of 3 components: a static dnsmasq config, a set of nginx configs (one per port-name mapping), and a script to manage the port configurations.
You can just install dnsmasq as normal and use the provided configuration. I use homebrew and just did brew install dnsmasq, copied dnsmasq.conf to /usr/local/etc/dnsmasq.conf, and followed the formula's instructions on how to get dnsamsq to automatically start on boot (sudo brew services start dnsmasq). The configuration itself has only one uncommened line: address=/.p/127.0.0.1. This causes dnsamsq to map any domain ending in ".p" to the local machine.
In addition, you need to configure the system to use the local dnsmasq as a DNS server. In OS X, go into System Preferences -> Network -> Advanced -> DNS and just add 127.0.0.1 as one of the DNS servers.
Install nginx with brew install nginx. Copy dns_proxy.conf to /usr/local/etc/nginx/.
The nginx config is divided into two parts: dns_proxy.conf has some high-level configuration and then includes all the port configurations. Start nginx with this config, nginx -c /usr/local/etc/nginx/dns_proxy.conf. Port configurations will go in dns-ports/ relative to this file.
Finally, portmap manages the mappings in dns-ports. When you add a mapping with the script, it modifies a simple text file called dns-services.txt, then generates files like dns-ports/ipython.conf based on the mustache template service.conf.mustache, then reloads nginx. To begin, copy the provided dns-services.txt over to /usr/local/etc/nginx/.