File Types

ESRI Shapefile:, a set of three files with the same name and the file extensions ".dbf", ".shp", and ".shx" respectively. All three files are required. Other files, such as ".prj" files, may be present, but My World doesn't require or use them.
The shapefile must contain unprojected latitude and longitude values, in decimal degrees, in the range -180 to 180. My World can automatically un-project shapefiles as they are imported, but you must know the original projection for this to work. Import the data using the "Import Data From File..." button or menu item to access the un-projection tool.
My World supports Point, Arc (line), Polygon and MultiPoint shapefiles.
Comma-Separated Values: a single text file with the extension ".csv", and comma (",") characters separating each value. The first row of the file should list the field names, and the first two columns must be latitude and longitude, respectively, in decimal degrees, in the range -180 to 180. When you import a CSV file, My World will give you the opportunity to re-arrange the columns so that latitude and longitude are in the proper place.
My World uses the same CSV format as Microsoft Excel. If you want a comma character to appear inside a cell value, the entire cell value must be enclosed in double quotes ("). To include a double-quote character inside a quoted value, use two double quotes in a row ("").
CSV files can only contain Point data.
Tab-Separated Values: a single text file with the extension ".tsv". Other requirements are the same as for comma-separated files, except that tab (" ") characters separate the values instead of comma characters.
If you want a tab character to appear inside a cell value, the entire cell value must be enclosed in double quotes ("). To include a double-quote character inside a quoted value, use two double quotes in a row ("").
TSV files can only contain Point data.
GPX Waypoint File: a single xml file with the extension ".gpx". This file is used for importing GPS data into My World. If you need to import data from a GPS device not supported by My World's built-in GPS importing functionality, the easiest way to accomplish it is to save the data in GPX format.
My World can read GPX files, but it does not support saving data in GPX format.
Click here for more information about the GPX file format.

Grid Data File Types

My World supports the following types of data files and/or folders for reading and writing grid data:

ASCII Grid file: a single file with the extension ".asc". Click here for a complete description of the ASCII Grid file format.
Folder of ASCII Grid files: a folder whose name ends with ".asc", containing a set of ASCII Grid files (whose names must also have the extension ".asc"). The files will be listed as fields of the layer, in alphabetical order by file name.
By default, the origin, cell size, and dimensions of the grid will be those of the file whose name is first alphabetically. Those settings can subsequently be adjusted in the Edit Layer Appearance window.
NetCDF file: a single file with the extension ".nc". My World only supports NetCDF files that use the Unidata Common Data Model. Also, My World can only read NetCDF files, it cannot currently write data in NetCDF format.
WorldWatcher Grid file: a single file with the extension ".wwf". WorldWatcher is a GIS that only handles grid data. It was the predecessor to My World GIS.
Folder of WorldWatcher files: a folder whose name ends with ".wwf", containing any number of WorldWatcher files (whose names must also have the extension ".wwf"). The files will be listed as fields of the layer, in alphabetical order by file name.
By default, the origin, cell size, and dimensions of the grid will be those of the file whose name is first alphabetically. Those settings can subsequently be adjusted in the Edit Layer Appearance window.

ASCII Grid files can be very memory-intensive, so it's better to save your data in WorldWatcher format once you have imported it into My World.

Image Data File Types

My World supports the following types of data files and/or folders for reading and writing image data:

JPEG image: a set of two files with the same name and the file extensions "jpg" and "jgw". The "jpg" file contains the image, and the "jgw" file is called the World File, and contains information about where on the map the image should be displayed.
TIFF image: a set of two files with the same name and the file extensions "tif" or "tiff" and "tfw". The "tif"/"tiff" file contains the image, and the "tfw" file is called the World File, and contains information about where on the map the image should be displayed.
My World can only read 1-band and 3-band TIFF files.
GeoTIFF image: a single file with the extension "tif" or "tiff".
Unfortunately, it's often impossible to distinguish GeoTIFF files from regular TIFF files without using a program to open them. Sometimes, a GeoTIFF will have ".geo." in its name, before the file extension, but not always.
If a "tfw" file is available, the file is probably a regular TIFF, and if not, then nothing is harmed by putting a "tfw" file with a GeoTIFF, so always keep the "tfw" file with the "tif" file if one is available.
My World can only read 1-band and 3-band GeoTIFF files.

Links to Dynamic Web Data

Using a dynamic web layer requires a working internet connection, on which port 80 (the port used for World Wide Web traffic) is not blocked.

WMS link: a single file with the extension "wms_xml". The file does not contain any data itself, just the address of a server that uses the Web Mapping Service (WMS) to dynamically provide images to My World.
THREDDS link: a single file with the extension "thl". The file does not contain any data itself, just a link to a THREDDS Server, which may provide either shape data or grid data.
THREDDS stands for Thematic Realtime Environmental Distributed Data Services and is a project of Unidata, a community of over 160 institutions vested in the common goal of sharing data, and tools to access and visualize that data, to support Earth-system education and research.
ArcIMS link: a single file with the extension "aims_lnk". The file does not contain any data itself, just a link to an ArcIMS Server, which may provide either shape data or dynamic image data.
ArcIMS Server is a commercial product produced by ESRI, and "ArcIMS" is a registered trademark of ESRI, Inc.
The ability to connect to an ArcIMS server is only present in registered copies of My World licensed for educational use.

Annotation File Types

My World supports the following types of data files and/or folders for reading and writing annotations:

My World Annotation file: a single file with the extension "mwa". Annotation files are My World-specific; no other programs are likely to be able to open them. My World Annotation files contain only Annotation data.

Additional Layer Files

In addition to the data files specific to the particular file type, My World will add two new files when it saves a layer. Both of these files will have the same name as the layer's data file(s), but a different file extension.

The Layer File ends with the extension ".myl" and contains information about how by My World should display the data file, such as default appearance settings for each field, and information about each field, such as its category and units.
If you lose or delete the Layer File, My World will still be able to read the data file, but any appearance settings you might have customized will be re-set to their default values.
The Data Documentation file is a text file (.txt) file which contains information about where the data came from, who owns it, and where to look for more information about it.

Project Files

My World can save two different types of Project files.

Project Folder (.m3vf): is a folder whose name ends in ".m3vf", containing all of the project's data files, included files, linked files, and all of its appearance settings.
Compressed Project File (.m3vz): is a single file, containing a m3vf folder that has been compressed using ZIP compression. You can examine the contents of an m3vz file by opening it using a program that can read ZIP files, such as WinZip.

While you are working on a project, it is best to save it as a m3vf folder, because reading and writing to the folder is faster, since it doesn't involve compressing the data.

If you want to share your project with someone using another computer, you should save it as an m3vz file, because the file will be smaller and it's easier to copy a single file from one computer to another than a whole folder full of files.

If you are downloading an m3vz file and your web browser unzips it without asking you (as Safari sometimes does, unfortunately), you can simply add ".m3vf" to the end of the name of the resulting folder and open it as a project folder in My World.

Tour Files

A tour is an HTML file that has been specially formatted for My World, to break it up into individual screens -- usually corresponding to steps the user should take as he or she navigates through the tour. Tour file names must end with the extension ".mwht".

In addition to standard HTML (including styles, but not CSS), My World tour files support several additional tags:

 indicates where the break between one tour section and the next should occur.
This tag may occur any number of times, but only between the <body> and </body> tags of the document.
 indicates the preferred window size for this tour.
This should occur only once, between the <head> and </head> tags of the document.

In addition to these special tags, My World also supports several special hypertext references you can use in your anchor tags in a tour document:

#project the link will cause the My World window to switch to Construct Mode, and select the "All Projects" Data Library from the Library menu.
Example: <a href="#project">Open Projects Library</a>
#welcome will close the current tour and re-open the Welcome Window.
Example: <a href="#welcome">Return To Welcome Window</a>

To see more examples of what a tour file should look like, take a look at the files in My World's tours folder.

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