OHM

Open History Mapper is a project, in its early stages, whose main goal is to be an open alternative to WALS.

The need

The primary use of OHM is to map linguistic features in modern languages (like WALS), but it can be used for so much more.

Features

The software should allow users to easily

• define arbitrary areas or points,
• specify a name for the areas or points from predefined [perhaps user-generated] data (e.g., a list of languages, etc.),
• map features to areas or points (even those defined by others),
• subgroup areas and points,
• display maps of the areas and points corresponding to various values of a feature, distinguished e.g. by colour,
  • ideally include customisable and complex symbology—e.g., provide ability to display multiple features at a time, using different distinguishing properties (colour, texture?, etc.),
  • include a customisable (in terms of look, content, and placement) legend, which may include the option to switch quickly between displaying different features,
  • include d3-like mouse-hover information on areas and points,
• [down the road] upload a scanned map and geo-reference it,
• export maps for use in publications.

Software

Mapping core

The mapping core that will be used hasn't been decided on yet. Some possibilities include the following:

• OpenLayers — very powerful, but a little tricky to use?
• Leaflet — fairly powerful, easy to use
• Polymaps — seems to do a lot of cool stuff, easy to use, powerful enough?

Base maps

There will need to be base maps in various projections. Some requirements follow:

• Projections that preserve size are ideal due to the nature of what these maps will be used for.
• Background layers should include physical maps of the earth as well as modern political boundaries and names. Use of one or the other or both should be easily user-switchable.