ICLR2014 has two publication tracks:

Conference Track: These papers are reviewed as standard conference papers. Papers should be between 6-9 pages in length. Accepted papers will be presented at the main conference as either an oral or poster presentation and will be included in the official ICLR2014 proceedings. 
A subset of accepted conference track papers will be selected to participate in a JMLR special topics issue on the subject of Representation Learning. Authors of the selected papers will be given an opportunity to extend their original submissions with supplementary material.

Workshop Track: Papers submitted to this track are ideally 2-3 pages long and describe late-breaking developments. This track is meant to carry on the tradition of the former Snowbird Learning Workshop. These papers are considered as workshop papers (and can be published elsewhere). They will be lightly reviewed by ICLR reviewers.

ICLR2014 Submission Instructions:

1. Authors should post their submissions (both conference and workshop tracks) on arXiv: http://arxiv.org
2. Once the arXiv paper is publicly visible (there can be an approx. 30 hour delay), authors should go to the openreview ICLR2014 website: http://openreview.net/iclr2014 to submit to either the conference track or the workshop track.
To register on the openreview ICLR2014 website, the submitting author requires a google account.