multiple Yii versions on a server possible?

I have Yii 1.0 installed on my linux server, can I install Yii 2.0 to co-exist with Yii 1.0?

Yes, of course: you can have as many versions as you have Yii 2 applications! And it is quite common.

Simply because Yii 2 uses Composer and thus local dependencies.

Thank you. So there will be no potential issues running both the versions right?

Yii 1 is using the old way: PHP include path, and normally globally installed and shared between applications.

Yii 2 is using Composer and is installed as a local dependency almost exclusively.

So, yes: no problems.

You can also have multiple versions of Yii 2 without incidence.

Thank you. That was very helpful information.

Yii 2 uses namespaces, so you can even use Yii 1 and Yii 2 together in the same application - although, I wage that you would rather not be doing that under normal circumstances.

I think PHP version may be a problem. 2.0 requires PHP 5.4 while 1.0 was made for 5.2. There could be compatibility issues running 1.0 on 5.4 since it wasn’t tested. If you’ve meant 1.1, that’s alright though to use PHP 7.

I completely overlooked that issue, of course!

Indeed, it will only work with Yii 1.1 and Yii 2.x

You can not use both together.