# Node Version Manager (nvm) for Windows

Manage multiple installations of node.js on a Windows computer.

**tl;dr** It's basically [nvm](https://github.com/creationix/nvm) for Windows.

There are situations where the ability to switch between different versions of Node.js can be very
useful and save a lot of time. For example, if you want to test a module you're developing with the latest
bleeding edge version without uninstalling the stable version of node, this utility can help.

### Installation

Download the latest installer from the [releases](https://github.com/coreybutler/nvm/releases).

### Usage

nvm for Windows is a command line tool. Simply type `nvm` in the console for help. The basic commands are:

- `nvm install <version>`: Install a specific version, i.e. `0.10.32`. This will also accept `latest`, which will install the latest stable version.
- `nvm uninstall <version>`: Uninstall a specific version.
- `nvm use <version>`: Switch to a specific version of node.
- `nvm list`: List the versions of node that are currently installed.
- `nvm on`: Turn on nvm management.
- `nvm off`: Turn off nvm entirely (does not uninstall anything).
- `nvm root <path>`: Specify the root directory where the different versions of node.js are stored. Leave <path> blank to see the current root.

### Gotcha!

Please note that any global npm modules you may have installed are **not** shared between the various versions of node.js you have installed.

---

## Why another version manager?

There are several version managers for node.js. Tools like [nvm](https://github.com/creationix/nvm) and [n](https://github.com/visionmedia/n)
are specifically designed for Mac OSX and Linux. [nvmw](https://github.com/hakobera/nvmw) and [nodist](https://github.com/marcelklehr/nodist)
are both designed for Windows. So, why another version manager for Windows?

Right around node 0.10.30, the installation structure changed a little, causing some issues with the other modules. Additionally, some users
struggle to install those modules. The architecture of most node managers on Windows focus primarily around the use of `bat` files, which
do some clever hackery to set environment variables. Some of them use node itself (once it's downloaded), which is admirable, but prone to
problems.

## What's the difference?

First and foremost, this version of nvm has no dependency on node. It's written in [Go](http://golang.org/), which is a much more structured
approach than using a `.bat` file. It does not rely on having an existing node installation. Plus, should the need arise, there is potential
for creating a Mac/Linux version with a substanially easier migration path than converting a bunch of `.bat --> .sh` logic.

The approach is also quite different. There are two general ideas for supporting multiple node installations and readily switching between them.
One is to modify the system `PATH` any time you switch versions. This always seemed a little hackish to me, and it has some quirks. The other option
is to use a symlink. This concept requires one to put the symlink in the system `PATH`, then just update the symlink to point to whichever node
installation directory you want to use. This is a more straightforward approach, and the one most people recommend.... until they realize just how much
of a pain symlinks are on Windows. In order to create/modify a symlink, you must be running as an admin, and you must get around Windows UAC (that
annoying prompt). Luckily, this is a challenge I already solved with some helper scripts in [node-windows](http://github.com/coreybutler/node-windows).
As a result, nvm for Windows maintains a single symlink that is put in the system `PATH` during installation. Switching to different versions of node
is a matter of switching the symlink target. As a result, this utility does **not** require you to run `nvm use x.x.x` every time you open a console
window, and it is automatically updated across all open console windows. It also persists between system reboots.

This version of of nvm for Windows comes with an installer, courtesy of a byproduct of the node-webkit work I did on [Fenix Web Server](http://fenixwebserver.com).

Overall, this project brings together some ideas, a few battle-hardened pieces of other modules, and support for newer versions of node.

## Why?

I needed it, plain and simple. Additionally, it's apparent that [support for multiple versions](https://github.com/joyent/node/issues/8075) is not
coming to node core, or even something they care about. It was also an excuse to play with Go :)

## License

MIT. See the LICENSE file.