Licences

All source is public. Every upstream commit below is on its own project site. Our patches and build files, and copies of the upstream source for the larger tools, are on one release: source-2026-10-20. Checksums are in SHA256SUMS.txt. Each tool runs in its own Web Worker or frame and talks to the rest of Studio only by messages.

Other tools, such as Yosys (ISC), netlistsvg (MIT), elkjs (EPL-2.0) and the gf180mcu cell data (Apache-2.0), are listed with their pinned versions in THIRD_PARTY.md.

To get source we have not listed, or if something here looks wrong, write to [email protected].

Icarus Verilog (simulation)

GPL-2.0

Source

VeriSim commit a275a9ac28c59db1130505973644c9a3754ec1d7 (Icarus compiled to WebAssembly). Original: https://github.com/steveicarus/iverilog

Our patches

None. The files are used as built.

Build steps

In the VeriSim repo; our copy in nishkam-icarus-wasm-build.tar.gz

Licence text

vendor/icarus/a275a9a/LICENSE

Magic (layout, DRC, GDS)

GPL-2.0

Source

https://github.com/RTimothyEdwards/magic commit bed8d4f

Our patches

None. Linked with two extra flags (function pointer casts, 10 MB stack).

Build steps

npm/build.sh --variant=notcl --release in emscripten/emsdk 3.1.74, then relink; see SOURCE.md

Licence text

vendor/magic/bed8d4f/LICENSE

Netgen (LVS) with Tcl 8.6.14

GPL (Netgen), BSD-style (Tcl)

Source

https://github.com/RTimothyEdwards/netgen commit 3cb047b (1.5.324); Tcl tag core-8-6-14

Our patches

One fix, a read after free in base/netcmp.c: netcmp-uaf.patch

Build steps

SOURCE.md

Licence text

vendor/netgen/3cb047b/LICENSE, vendor/netgen/3cb047b/TCL_LICENSE

qrouter, vlog2Cel, addspacers (routing)

GPL-2.0

Source

https://github.com/RTimothyEdwards/qrouter commit c8f1111; qflow commit 52ecda1

Our patches

Folder c8f1111/ is unmodified. Folder c8f1111-drc/ adds one change in main.c: drc-blocks.patch

Build steps

build.sh, SOURCE.md

Licence text

vendor/qrouter/c8f1111/LICENSE

graywolf (placement)

GPL-2.0-or-later with Yale conditions

Source

https://github.com/RTimothyEdwards/graywolf commit 33fbcaa

Our patches

wasm.patch (integer types, prototypes, in-process replacement for system())

Build steps

build.sh, SOURCE.md

Licence text

vendor/graywolf/33fbcaa/LICENSE, vendor/graywolf/33fbcaa/COPYING

OpenSTA (timing and power)

GPL-3.0

Source

https://github.com/parallaxsw/OpenSTA commit defec0bda32fe6c95074e8da417cb56e344874b5; CUDD https://github.com/The-OpenROAD-Project/cudd commit d47718f

Our patches

None to OpenSTA. Our own start-up file: vendor/opensta/defec0b/main_wasm.cc

Build steps

SOURCE.md lists every command

Licence text

vendor/opensta/defec0b/LICENSE

OpenROAD (place, route, clock tree, parasitics) with OpenSTA inside

BSD-3-Clause; GPL-3.0 because OpenSTA is linked in, so we treat the whole file as GPL-3.0

Source (current)

https://github.com/The-OpenROAD-Project/OpenROAD commit 6f3f28cc85407d71ba64a550cca194d8a6a01c1c, with its OpenSTA at 84c4d7e133d3b1a54352c97c6a5df3140c71c78c

Source (older, still served)

Same repo, commit 61932e897ed1171d85734f2a54064965f691d758, OpenSTA defec0b. Full tarball: https://github.com/yashv373/nishkam-tool/releases/download/source-2026-10-20/OpenROAD-61932e8.tar.gz

Our patches

For 6f3f28c: openroad-6f3f28c-wasm.patch and openroad-6f3f28c-rcx-psm.patch. For 61932e8: openroad-61932e8-wasm.patch. All in nishkam-openroad-6f3f28c-wasm-build.tar.gz (folder tools/openroad-pnr).

Build steps

BUILD.md in that archive (written for 61932e8; 6f3f28c uses the same libraries plus a small Boost serialization library), and SOURCE.md

Licence text

vendor/openroad-pnr/61932e8/LICENSE.OpenROAD and the other LICENSE.* files in that folder

KLayout through kwasm (GDS viewer)

GPL-3.0

Source

Python wheel kwasm 0.3.1 (sha256 4cbd66d752c577f11277a6259bdcf390462f392e1518f66ca9473363f75db13a); copy at https://github.com/yashv373/nishkam-tool/releases/download/source-2026-10-20/kwasm-0.3.1-py3-none-any.whl

Our patches

None. Our page around it (host.html) is separate code that talks to it by messages.

Build steps

nishkam-kwasm-wasm-build.tar.gz

Licence text

vendor/kwasm/0.3.1/LICENSE

Surfer (waveforms)

EUPL-1.2

Source

https://gitlab.com/surfer-project/surfer commit 1cdbaa9514ea15b06a186d23979dbb38ab774ad1; copy at https://github.com/yashv373/nishkam-tool/releases/download/source-2026-10-20/surfer-1cdbaa9.tar.gz

Our patches

One line in index.html that turns the service worker off.

Build steps

nishkam-surfer-wasm-build.tar.gz, SOURCE.md

Licence text

vendor/surfer/20261009/LICENSE

Verilator through verilator-wasm (lint)

LGPL-3.0 or Artistic-2.0 (Verilator); MIT (wrapper)

Source

Not served by us: the browser loads the npm package verilator-wasm 1.0.0 from jsDelivr. Its source is https://github.com/wavedrom/verilator-wasm and the Verilator fork pinned in its verilator.json (branch wasi/pr-wasi-support; revision e6cee9d54 on the main branch today. We have not confirmed the revision used for 1.0.0).

Our patches

None.

Build steps

In the verilator-wasm repo.

Licence text

Inside the npm package: LICENSES/LGPL-3.0-only.txt

Verilator simulation runtime and @yowasp/clang (Verilator simulation)

LGPL-3.0-only OR Artistic-2.0 (Verilator headers and runtime); ISC (@yowasp/clang packaging); Apache-2.0 with LLVM exception (LLVM, Clang, LLD); Apache-2.0 / MIT (libc++, libc++abi, wasi-libc)

Source

Verilator: github.com/verilator/verilator commit e6cee9d54c8af74fbf1ade07aac4f4343249acbd (5.051 devel, the commit [email protected] is built from). We serve its include/*.h headers and a libverilated.a we compiled from its verilated*.cpp files, from web/vendor/verilator-sim/5.051-e6cee9d/. The compiler is not served by us: the browser loads @yowasp/clang 22.0.0-git20542-10 from jsDelivr; source github.com/YoWASP/clang (pins llvm-project).

Our patches

None to Verilator or LLVM. Two small files only we wrote are linked into libverilated.a: a stub for dup/dup2 and a thread_local destructor hook (WASI lacks both); the generated main() is rewritten from three to two arguments at run time.

Build steps

In web/vendor/verilator-sim/5.051-e6cee9d/SOURCE.md and tools/vsim-spike/ (-std=c++20 -O1 -fno-exceptions).

Licence text

Verilator: LICENSES/LGPL-3.0-only.txt in the verilator-wasm package; LLVM: llvm.org/LICENSE.txt