OpossumUI is a tool to

• discover open source software used in applications.
• review licenses.
• generate reports from an open source code scan.

• use of multiple scanners (open source and/or proprietary).
• currently integrates with OSS Review Toolkit, FOSSLight and ScanCode.
• unified interface for browsing scanner evidence.
• simple navigation through the codebase’s file tree.
• create attributions for individual files or groups.

• A team performing audits for open source license compliance.
• Producing legal docs such as inventory (BOMs) and license conflicts that need to be remediated.
• OpossumUI can be used to visually inspect (QA) existing attributions, identify any false positives or incorrect attributions by manual selection and improve existing data.
• To aid M&A due diligence activities. OpossumUI can be used by acquirers for blind audits of intellectual property, since only compliance-relevant metadata is exposed in the app without the need to ever share the source code.

OpossumUI was developed with the goal to build a tool for managing and combining open source compliance data from different sources. While existing analysis tools for software compliance can provide good information, using multiple of such tools often leads to huge amounts of data due to an increased detection rate. Even though the results can be merged and noise can be filtered through automatic tools, final manual revisions are often necessary. So, OpossumUI was born: A light-weight app for review of compliance information for large codebases.

To integrate well with different analysis tools, different converters are provided to generate input files in json format that can be opened with OpossumUI. After completing the review process with OpossumUI, the information can be outputted in different formats.

To work with OpossumUI, an input file can be opened to visualize and edit license compliance data of a project. Input files typically have the file ending .opossum, while opening the deprecated file format that has the file ending .json is still supported. In this case the app will inform the user that the deprecated file format is automatically converted to the new file format.

Result files from ScanCode and SCANOSS can be converted into OpossumUI input files using opossum-tool/opossum.lib.hs. This tool can also generate OpossumUI input files from spdx and merge several OpossumUI input files.

Result files (yaml / json) from the OSS Review Toolkit can be converted into OpossumUI input files via a reporter. It uses metadata from the analyzer as well as scan results from the scanner. The implementation is in oss-review-toolkit/ort and the new reporter output is called Opossum.

For details of the file format, see file formats.

Check out our short getting started video:

Download the latest release for your OS from GitHub.

Run the executable OpossumUI-for-linux.AppImage

Run OpossumUI in OpossumUI-for-mac.zip.

Run OpossumUI-for-win.exe to install the OpossumUI. Then open OpossumUI from the start menu.

Check out our short video, which presents a basic workflow.

For an in-depth explanation, please read the Users's Guide.

Files with a .opossum extension are zip-archives which contain an input.json (must be provided) together with an output.json (optional). JSON schemas for both the input and output files are available. Example files can be found under example files.

It has to be generated through external tools and provided to the app. Contains 5 main fields:

• metadata: contains some project-level information,
• resources: defines the file tree,
• externalAttributions: contains all attributions which are provided as signals (preselected signals will be automatically used by the app to create attributions in the output file),
• resourcesToAttributions: links attributions to file paths,
• frequentlicenses: A list of licenses that can be selected in a dropdown when the user enters a license name.

There are additional fields which are optional:

• attributionBreakpoints: a list of folder paths where attribution inference stops, e.g. node_modules."

• filesWithChildren: a list of folders that are treated as files. This can be used to attach another file tree to files like package.json, usually also setting an attribution breakpoint.

• baseUrlsForSources: a map from paths to the respective base url. The base url should contain a {path} placeholder. E.g.

  "baseUrlsForSources": {
    "/": "https://github.com/opossum-tool/opossumUI/blob/main/{path}"
  }

• externalAttributionSources: used to store a mapping of short names for attribution sources to full names and priorities used for sorting in the PackagePanel. Entries with higher numbers have a higher priority. E.g.:

  "externalAttributionSources": {
    "SC": {
      "name": "ScanCode",
      "priority": 1
    }
  }

Contains four main fields:

• metadata: contains some project-level information,
• manualAttributions: contains all attributions created by the user or preselected,
• resourcesToAttributions: links attributions to file paths,
• resolvedExternalAttributions: used to store which signal attributions have been resolved, as they are hidden in the UI.

In addition to the default output file, OpossumUI provides the following export options.

An SPDX document can be exported in the json and the yaml format through the Export ⟶ SPDX (yaml) and SPDX (json) option in the File menu.

These can be exported through the Export ⟶ Compact / Detailed component list option in the File menu. Both component list files contain a list of all attributions that are present in the project, including package name, version, copyright, license name and URL. In addition, the detailed component list is more comprehensive and includes the PURL and its subcomponents, as well as the license texts.

This can be exported through the Export ⟶ Follow-Up option in the File menu. Similar to the component list, it contains attributions with licenses flagged for legal review through the Follow-Up checkbox in the UI.

SPDX License Expressions are only partially supported at the moment. Currently, a license expression can only be entered as license name of a package. The full license text of the different licenses (e.g. GPL-2.0-only OR BSD-2-Clause) that apply should also be entered in the license text field.

Contributions to the project are welcome. See Contributing.

OpossumUI is licensed under Apache-2.0, documentation is licensed under CC0-1.0. For contributions, we use the Developer Certificate of Origin (DCO) process via sign-offs in every commit, to help ensure licensing criteria are met.