LTTng UST (User-Space Tracer) is provided under the terms of the GNU Lesser General Public License v2.1 only: SPDX-License-Identifier: LGPL-2.1-only According with: LICENSES/LGPL-2.1.txt It is intended to allow use of the tracer API from both free and proprietary software. Public header files, and LTTng filter runtime code are provided under the terms of the MIT License: SPDX-License-Identifier: MIT According with: LICENSES/MIT.txt The UST control library is provided under the terms of the GNU General Public License v2.0 only: SPDX-License-Identifier: GPL-2.0-only According with: LICENSES/GPL-2.0-only.txt This applies to: src/lib/lttng-ust-ctl/ust-ctl-private.h src/lib/lttng-ust-ctl/ustctl.c The snprintf code is provided under the terms of the BSD 3-Clause "New" or "Revised" License: SPDX-License-Identifier: BSD-3-Clause According with: LICENSES/BSD-3-Clause.txt This applies to: snprintf/fflush.c snprintf/fileext.h snprintf/floatio.h snprintf/fvwrite.c snprintf/fvwrite.h snprintf/local.h snprintf/mbrtowc_sb.c snprintf/snprintf.c snprintf/various.h snprintf/vfprintf.c snprintf/wcio.h:5 snprintf/wsetup.c The TAP test library is provided under the terms of the BSD 2-Clause "Simplified" License: SPDX-License-Identifier: BSD-2-Clause According with: LICENSES/BSD-2-Clause.txt They are only used when running the tests in the source tree. This applies to: tests/utils/tap.h tests/utils/tap.c The BASH TAP library is provided under the terms of the GNU General Public License v3.0 or later: SPDX-License-Identifier: GPL-3.0-or-later According with: LICENSES/GPL-3.0-or-later.txt It's only used when running the tests in the source tree. This applies to: tests/utils/tap.sh In addition, other licenses may also apply, see SPDX-License-Identifier in individual files.