1. Introduction

2. Observations

3. Data reduction, extraction of spectra, and identification of emission-line stars
3.2. Identification of emission-line stars: the Album code
3.3. Efficiency of Hα emission detection

4. Astrometry, photometry, and spectral classification
4.1. WFI SMC data
4.2. Comparison data for the Galaxy

5. Results and discussion
5.1. Topology of global HR diagrams
5.2. Colour excesses of emission-line stars
5.3. Frequency of Be stars as a function of local star density
5.4. The Be phenomenon: SMC vs. Galaxy
5.5. The Be phenomenon as a function of spectral type
5.6. Evolution and age

6. Summary and conclusions