Simplest way(s) to make a Julia package available to others

Any package source code can be manually placed in .julia/MyPackage. This can be done by unzipping a file, or checking out the package source from its repository manually. Once that is done, require("MyPackge") will work, just as with any official packages.

If you want to get users to try out Pkg.add("MyPackage"), you will need to provide them with your own METADATA repository. Clone the official repository, add your own package as usual. Then and ask users to initialise their julia package installation with Pkg.init("url to metdata git repository"). Once that is done, Pkg.add("MyPackage") will install the package from its own private git repository.