Gtopo is a program for viewing the National Geographic Survey's
Topographic Map sets on a computer running linux
(or on a MAC running OS-X, or any computer with GTK).
I also have a program for android that I use on my phone and tablet. See the link below.
I am not giving away the maps themselves, just providing an alternate piece of software. Gtopo uses GTK-2.0 and provides a simple and nice viewer for map images. The program was written in July of 2007 and is now quite stable, but receiving occasional maintenance.
I am pleased if people download and use it and would be grateful to know how it works for them. I run it primarily on a 64 bit x86 linux system (under Fedora 24).
It now works quite well for viewing the TOPO! series files, and current development is focused on allowing it to obtain maps (and photos) from terraserver, which among other things, will make it useful for people who do not own TOPO! series collections (stay tuned!).
If you want to build gtopo on your machine, by far the easiest thing to do these days is the clone the sources from github. I still provide tarballs here, but am likely to discontinue that at some point in the future. To clone the sources:
git clone https://github.com/trebisky/gtopo.git
The following link is where I have collected a lot of reference information. None of it is essential reading if you just want to use gtopo, but it should be of interest to people who want to learn about maps, GIS, gtopo internals, file formats, Terraserver, the USGS MRDS database and more!
Subsequent to developing gtopo, I became interested in the idea of using an android tablet to run something like gtopo. This led to the development of atopo (written in Java for the Android). After using it for a while on the tablet, I realized that it would be even more convenient on my android phone.
I have not placed "atopo" on the android store because there is a fairly complex process of putting the map files on an SD card (and most people don't own the maps and would be frustrated). Contact me though if you are interested.
Having the maps on a card in the unit is essential for people like me who operate in remote areas without internet connectivity.
Gtopo / firstname.lastname@example.org