This a follow up article to Setting up ownCloud on Slackware 14.0 (part 1 - the server) and a prelude to Setting up ownCloud on Slackware 14.0 (part 3 - Encryption using SSL) although you could setup the SSL/HTTPS on the server before setting up the client.

Once the server is setup and you can login to ownCloud through the web browser the next thing to do is to install the ownCloud client application on any required user machines (there is also an ownCloud app available for use on Windows, MacOS and tablets/phones running Android and IOS). Installing the client application allows for users to sync their data/documents/media across all machines or devices they own.

The clients for Windows, Mac and Linux(CentOS/RHEL, Fedora, openSUSE, Ubuntu, Debian) and the source can be downloaded from owncloud.org/sync-clients.

Because there is not package provided for Slackware we can install the client from source. There are two packages required to build and install the client they are ocsync and mirall. If you are using Slackpkg+ (and you should be!!!) and have alienbobs repositories you can install through slackpkg using:
# slackpkg install ocsync

and
# slackpkg install mirall

These versions are out of date, ocsync-0.80 and mirall-1.3.0 whereas the latest versions are ocsync-0.90.4 and mirall-1.4.2, but these old version still work fine.

I tried to build the newest sources both changing and using the slackbuilds and using the build instructions but both times it failed with an error (missing a header file) and I haven't had time to investigate more.

Using the client.

The client is accessed by entering owncloud on the command line, this brings up dialogs that allows you to enter the login details for the server and the user credentials and to choose where you want the sync folder to be.