ECL is distributed under the GNU LGPL, which allows for commercial uses of the software. A more precise description is given in the Copyright notice which is shipped with ECL.
---- BEGINNING OF COPYRIGHT FOR THE ECL CORE ENVIRONMENT ------------ Copyright (c) 2015, Daniel Kochmański Copyright (c) 2000, Juan Jose Garcia Ripoll Copyright (c) 1990, 1991, 1993 Giuseppe Attardi Copyright (c) 1984 Taiichi Yuasa and Masami Hagiya All Rights Reserved ECL is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version; see file 'Copying'. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. PLEASE NOTE THAT: This license covers all of the ECL program except for the files src/lsp/loop.lsp ; Symbolic's LOOP macro src/lsp/pprint.lsp ; CMUCL's pretty printer src/lsp/format.lsp ; CMUCL's format and the directories contrib/ ; User contributed extensions Look the precise copyright of these extensions in the corresponding files. Report bugs, comments, suggestions to the ecl mailing list: firstname.lastname@example.org. ---- END OF COPYRIGHT FOR THE ECL CORE ENVIRONMENT ------------------