Will there be any copyright issue if we use an existing product&#39;s name? In software industry, while naming a new app or a product, will there be any copyright issue if we use an existing name?
The term in your question, "use an existing name", is pretty broad. Do you propose to say, "Compatible with Microsoft Lync"? Or will you actually name your product "Lync"? The first option is likely safe. The second one looks like a Trademark infringement more than a copyright issue. And "Lync" is distinctive enough, you probably won't win. However, if you propose to name your product "Messenger", you're slightly better off because "messenger" is a generic term in the English Language, even if Facebook adopted it for their product. The major criteria would be if your chosen name is likely to cause confusion with Facebook's product.
Germany may be different, however in the United States this would be considered work-for-hire and the employer would be the rightful owner of the source code. Regardless of jurisdiction, and from a more practical point of view, you are better off not having a copy of the source code. Using it as reference or example in the future could easily turn into (unintentional) copyright infringement. If, in the future, you write code you would like to be able to freely keep and reuse in any project, make sure the owner/employer licenses it using something like the BSD, MIT, or ISC license.
What you are missing is that the original copyright holder can give permission to make derivative works with strings attached. There is no automatic right to derive something from a copyrighted work. Those strings could include constraints on what you create in the process of making the derivative work. Yes it is a string limiting what you can do with something you own, but you would have been warned in the license and had the choice to start from scratch. People do create work-alike software with no copyright strings using two teams and a &quot;clean room&quot; design process. It is a lot harder than modifying something another person has developed. Also, law and someone's understanding of morals need not be aligned at all. And, in patent law, just creating something all by yourself from scratch does not give you ownership. If someone else did it first and got a patent you can't make the item you might think you own. IP law is complex and looking for &quot;fundamentals&quot; may not get you anywhere.
Yes you can. The pieces of information you are going to include are facts. Facts are not copyrightable. The names will be trademarks but you will not be pretending to have any connection with them, so just using them for reference is fine.
There are two common approaches. The first approach is simply to let copyright law apply. Under the default terms, the IT provider has no rights to copy your software. Running software is allowed, of course, and not a problem that you need to deal with vis-a-vis the IT provider. You still can sue them if they copy your software, even in the absence of a contract. That is the chief function of copyright, after all! The second approach is to allow the customer to subcontract third parties to act on behalf of them, while acknowledging that such subcontracting does not dissolve them from any responsibilities towards you. In other words, if the 3rd party would do something unauthorized, you have a claim towards the customer and they have a distinct but related claim towards their IT supplier.
This is permitted so long as it doesn't violate a valid trademark or service mark (or a few equivalent rights in names that are comparable such as collective rights to market beef under the name &quot;Waygu&quot; only if it is produced in a certain area of Japan under Japanese law) that covers goods or services of the same type in the same economic market. A trademark arises either when a term acquires a &quot;secondary meaning&quot; associating its use in connection with a particular kind of good or services in a particular market with a particular provider of that good or that service, or by registration of the trademark or service mark. &quot;Tresh&quot; and &quot;Cassiopeia&quot; are not terms that inherently are related to software, so they are permissible to use as trademarks for software unless someone else already has established trademark protection for them.
It is not possible to say that this is generally fair use, although sometimes it would be. A copy for personal use is still a copyright right violation on its face, and fair use does not categorically exclude non-commercial or personal use of copyrighted works. It is a highly fact specific inquiry. The likelihood of anyone discovering that you have done so and deciding to sue over it is slight, but that doesn't mean that there isn't potential copyright infringement liability. Compare this to speeding. People do it all the time, and even driving one mile per hour above the speed limit is still a traffic violation. But it is rare for less serious violations to be ticketed.
Exactly the same way it works over all other content There are no special classes of copyright, there’s just copyright. What a user of a service may do with copyright materials will be spelled out in the licence. If there is no licence, then they are left with fair use/fair dealing.