1. INTRODUCTION

2. JWST/NIRISS OBSERVATIONS
2.1. Target field
2.2. Setup and expectations

3. DATA REDUCTION AND SPECTROSCOPY
3.1. Image processing
3.2. Source catalog and photometry
3.3. Extraction of spectra
3.4. Comparison with brown dwarf spectra

4. SELECTION AND ANALYSIS OF CANDIDATE PLANETARY-MASS OBJECTS

5. SEARCHING FOR VERY LOW MASS BINARIES
5.1. Survey for visual pairs
5.2. Results of the binary search

6. DISCUSSION: FFPMOs AND THEIR FORMATION
6.1. The fraction of FFPMOs in NGC1333
6.2. Comparison with other regions
6.3. Comparison with simulations

7. SUMMARY