Available published spectra have been combined to form a library of digital stellar spectra spanning 1150 - 25000 A with a sampling interval of 5 A and a resolution of ~500. The library was constructed to enable synthesis and modeling of the integrated light from composite populations. The library consists of 131 flux-calibrated spectra, encompassing all normal spectral types and luminosity classes at solar abundance, plus metal-weak and metal-rich F-K dwarfs and G-K giants. Each library spectrum was formed by combining data from several sources overlapping in wavelength coverage. The data sources are listed in file srclist.doc, and the specific components used to form each spectrum are identified in file complist.doc. The library has complete spectral coverage from 1150 - 10620 A for all spectra and to 25000 A for about half of them, mainly later types of solar abundance. Missing spectral coverage in the infrared consists of a smooth energy distribution formed from standard colors for the relevant types. The library spectra are each given as normalized F(lambda) vs. wavelength in A: each spectrum is normalized to 1.0 at 5556 A. Spectra are organized in two groups of 131 files each; the files are named according to the spectral type, luminosity class and metallicity. The first group of files, designated UVILIB, contains the final combined spectra from 1150 - 11620 A. The second set of files, UVKLIB, extends the UVILIB spectra out to 25000 A, as described above. The data files contain the wavelength, normalized flux and standard deviation for the final combined spectrum in the first three columns. Subsequent columns contain the normalized flux for component spectra which were used to make the final spectrum. Columns which contain these component spectra are labelled according to a code which specifies the source of that spectrum (see complist.doc for more detail) -- UVILIB component codes Code Occasional Alternate Reference source Codes fsv Sviderskiene 1988, Cat. <VI/50> fi (IUE) Heck et al. 1984, Cat. <III/83> fg Gunn & Stryker 1983, Cat. <III/88> fk Kiehling 1987, Cat. <III/124> fj Jacoby, Hunter & Christian 1984, Cat. <III/92> fs Silva & Cornell 1992, Cat. <III/166> fp Pickles 1985, Cat. <VII/102> fn (N6522) Pickles & van der Kruit 1990 (1990A&AS...84..421P) fr fr1, fr2 Serote Roos, Boisson & Joly 1996, Cat. <J/A+AS/117/93> fd fdd1, fdd2; fd3, fd4 Danks & Dennefeld 1994 (1994PASP..106..382D) UVKLIB component codes Code Reference source fh spectrum from UVILIB fse interpolated spectrum based on standardized flux points fl Lancon & Rocca-Volmerange 1992, Cat. <III/196> fd Dallier, Boisson & Joly 1996, Cat. <J/A+AS/116/239> fk Kleinmann & Hall 1986 (1986ApJS...62..501K) fc Cohen et al. (1995, 1996a, 1996b); Cat. <J/AJ/110/275>, <J/AJ/112/241>, <J/AJ/112/2274> fm Fluks et al. 1994, Cat. <J/A+AS/105/311> M giant spectra in UVKLIB include the synthetic M0-M10 MK type spectra from Fluks et. al. (1994), and are a combination of these and the UVILIB spectra in the range 1150-10620A. M0-M8 III are the only cases where the 1150-10500A data differ between UVILIB and UVKLIB. M9 and M10 III spectra are exclusively synthetic spectra from Fluks et. al. (1994) in both libraries. In addition to the spectrum library itself, synthetic photometry and selected local equivalent widths & magnitude indices are provided in tables synphot.dat and lew.dat. The standard infrared colors used to form the smooth energy curves used in UVKLIB spectra are listed in irstphot.dat. Further documentation details are available in the *.doc files as described below in the table notes in this ReadMe.