SimPL-2.0 restates GPLv2 in one page of plain English. The wording is short. The obligations are the full strong copyleft ones.
On this page
What it does
The Simple Public License 2.0 is GPL version 2 written out in about one page of ordinary English. It was drafted to be readable, not to be lighter. If you give the software to someone, you give them the source of the whole program under SimPL as well, and the notices stay intact. The plain wording is the only difference a reader will notice. The legal effect it aims at is the same strong copyleft you would plan for with the GPL, so plan for it the same way.
Details
SimPL-2.0 is rare, and the rarity is the risk. A reviewer who has never seen it reads four short paragraphs, recognizes no GPL clause, and waves the component through. The correct reaction is the opposite: treat it exactly as you would treat GPL-2.0 in the same place in your product. If you only host the software, there is nothing to do. If you give it to anyone, the source of the whole program goes with it.
Pros
- Clear rules for sharing improvements. Recipients of a binary can ask for the corresponding source.
- Widely understood by legal and engineering. Compatibility questions have a large public record.
Cons
- Shipping a combined binary usually means offering corresponding source under the same license.
- Mixing with Apache-2.0 or other patents-bearing licenses is a known compatibility trap on older GPL versions.
What it allows and requires
Choose a category to see the full grant in one scannable list. Permissions show what the license allows, limits show what it withholds, and obligations show the conditions your release process must satisfy.
Permissions
Commercial use
You may ship the code inside a paid product. The license does not restrict commercial use.
Modify
You may change the code, including keeping those changes private, unless a later obligation says otherwise.
Distribute
You may give copies to others. Distribution is what usually turns notice and source duties into real work.
Private use
Use inside your company, including internal forks, does not by itself trigger distribution duties.
Limits
Hold liable
The authors disclaim warranty. Recipients cannot hold them liable for damages arising from the software, except where law forbids that disclaimer.
Use trademark
The license is not a trademark license. Names, logos and product marks stay with their owners unless a separate grant says otherwise.
Open your product
Copyleft can reach a combined work you distribute, not only the original files. How far that reaches in your stack is a counsel question.
Network copyleft
Classic GPL has no network clause. Offering the program as a hosted service, without distributing a copy, does not by itself trigger the source offer.
Obligations
Include copyright
Keep copyright notices on distributed copies.
Include license
Give recipients a copy of the license with the program.
Disclose source
When you distribute a binary of a covered work, corresponding source has to be offered in the way the license describes.
Same license
The combined work you distribute has to stay under this license. You cannot close the covered work with a more restrictive grant.
What SimPL-2.0 requires when you ship
When you distribute a binary that includes SimPL-2.0 code, notice still travels with the copy, and the corresponding source has to be available under the same license. Internal use without a copy leaving the company is a different situation. The list below is the shipping work: what a recipient of that binary can demand, and what you record so a buyer can see it.
You meet the terms while the software stays on your own machines. Like GPL-2.0, SimPL has no network clause, so a hosted service triggers no source duty.
You meet them on distribution when everyone you give the software to can get the source of the whole program, under SimPL, and not only the parts you changed.
You meet the notice terms when the original copyright and license notices stay in the copies you pass on, unchanged and easy to find.
You have taken the conservative route on compatibility when SimPL code stays out of a GPL work. The FSF has not listed SimPL as GPL-compatible, so a combination needs counsel.
The duties named in SimPL-2.0
Notice still travels with the copy. On top of that, SimPL-2.0 names a source duty. These are the conditions in the text. The how-to above is when they become real work.
Include copyright
Keep copyright notices on distributed copies.
Include license
Give recipients a copy of the license with the program.
Disclose source
When you distribute a binary of a covered work, corresponding source has to be offered in the way the license describes.
Same license
The combined work you distribute has to stay under this license. You cannot close the covered work with a more restrictive grant.
Things to be aware of
- Reading the friendly one-page wording as a sign that the obligations are lighter. They are not. Size the plan on GPL-2.0 and the license will not surprise you later.
- Assuming SimPL and GPL code can be merged because the two texts say similar things. No authority has blessed that combination, so ask counsel before you build on it.
- Skipping the component because the package is tiny. Strong copyleft does not scale with line count: one file inside a shipped binary carries the same duty as a whole framework.
What the Simple Public License 2.0 does not do
Search results often flatten Simple Public License 2.0 into a slogan. These are the usual misreads. SimPL-2.0 is a grant with conditions, not a permission to skip the paperwork below.
- the Simple Public License 2.0 does not let you keep the combined program closed if you distribute it. The reciprocal duty reaches the work as a whole.
- Network use alone is not distribution for GPL-family licenses. Running a GPL program as SaaS, without AGPL, does not by itself trigger the source duty.
How SimPL-2.0 differs from nearby licenses
These licenses are often confused with SimPL-2.0, but their release duties differ. Each row summarizes what the license requires when you ship. Open the linked page for the full checklist.
- SimPL-2.0
- SimPL-2.0 restates GPLv2 in one page of plain English. The wording is short. The obligations are the full strong copyleft ones.
- GPL-2.0-or-later
- GPL-2.0 asks for source when you hand someone a binary. Running it on your own servers triggers nothing. The trigger is shipping a copy, not merely using it.
Common questions about Simple Public License 2.0
Answers to common questions about what Simple Public License 2.0 requires, when its duties apply, and what evidence belongs with a release.
What is the Simple Public License 2.0?
The Simple Public License 2.0 is GPL version 2 written out in about one page of ordinary English. It was drafted to be readable, not to be lighter. If you give the software to someone, you give them the source of the whole program under SimPL as well, and the notices stay intact. The plain wording is the only difference a reader will notice. The legal effect it aims at is the same strong copyleft you would plan for with the GPL, so plan for it the same way.
What does SimPL-2.0 require when you ship a product?
You meet the terms while the software stays on your own machines. Like GPL-2.0, SimPL has no network clause, so a hosted service triggers no source duty. You meet them on distribution when everyone you give the software to can get the source of the whole program, under SimPL, and not only the parts you changed. You meet the notice terms when the original copyright and license notices stay in the copies you pass on, unchanged and easy to find. You have taken the conservative route on compatibility when SimPL code stays out of a GPL work. The FSF has not listed SimPL as GPL-compatible, so a combination needs counsel.
Does hosting a product that uses SimPL-2.0 trigger extra duties?
Hosting alone usually does not trigger the source duty for SimPL-2.0. Shipping a binary, a container, or an on-prem build does. Notice still travels with any copy you hand over.
Does linking to SimPL-2.0 force me to open my application?
For strong copyleft such as SimPL-2.0, the FSF reads static and dynamic linking as one combined work when you distribute the result. Shipping a binary that includes SimPL-2.0 code is the usual trigger. Internal use with no copy leaving the company is a different situation. Read the actual text, not the family nickname.
What is corresponding source for SimPL-2.0?
Corresponding source is the source a recipient needs to build and run the same binary, including scripts and interface files the license names. Hosting a repository URL can be an offer. The offer has to match what you actually shipped. SourceTrust records that a person on your team confirmed the offer. It does not publish your source and does not host a mirror.
How is SimPL-2.0 different from GNU GPL v2.0 or later?
SimPL-2.0 asks this: SimPL-2.0 restates GPLv2 in one page of plain English. The wording is short. The obligations are the full strong copyleft ones. GNU GPL v2.0 or later asks this: GPL-2.0 asks for source when you hand someone a binary. Running it on your own servers triggers nothing. The trigger is shipping a copy, not merely using it. Open the GNU GPL v2.0 or later page for what that license requires when you ship. Do not treat the SPDX ids as interchangeable because the short names look similar.
Where do I record SimPL-2.0 for a buyer?
The catalog marks SimPL-2.0 as copyleft, so it behaves like the GPL rows. A source offer item appears on the project checklist when the distribution context is Distributed binary or Mixed, and a person on your team confirms it before the project can publish. Only a confirmed match auto-fills the license text. Anything else lands as unconfirmed, mismatch or not found and waits for you to accept it.
Where do I record SimPL-2.0 for a buyer?
The catalog marks SimPL-2.0 as copyleft, so it behaves like the GPL rows. A source offer item appears on the project checklist when the distribution context is Distributed binary or Mixed, and a person on your team confirms it before the project can publish.
Only a confirmed match auto-fills the license text. Anything else lands as unconfirmed, mismatch or not found and waits for you to accept it.
Read /docs/reviewing-component for that flow.
See also
The hub is the pillar for this cluster. Sibling licenses are the other spokes. Product FAQ links explain how SourceTrust records the duty, not the license text itself.
Practical guidance for procurement review, not legal advice. Confirm high-stakes use with counsel.