How do I open a Photoshop PSD in a vector editor?
Vectornation by Zaweba opens PSD and PSB files with their layers, and File > Export > PSD writes a layered file back for a Photoshop user.

Open it like any other file. Vectornation by Zaweba reads Photoshop PSD files, and the larger PSB format too, with their layers kept separate, so you can work on the parts of the picture rather than one flattened image. When the work needs to go back to a Photoshop user, File > Export > PSD writes a layered file.
Designers are sent PSD files all the time: a mock-up from a photographer, a background from a web team, a product shot with the cut-out on its own layer. Being able to open them directly, without a subscription to the program that made them, saves a lot of back and forth.
What you get when it opens
The layers come in as layers. A cut-out product, a shadow and a background stay apart, so you can hide the background, move the product or put your own vector artwork between them.
Remember what a PSD is: pixels. Opening it in a vector editor does not turn those pixels into shapes. They are images on layers, and they look as sharp as their resolution allows. Enlarging them will soften them, the same as anywhere else.
Combining it with vector work
The usual job is to add crisp vector parts on top of a photographic base: type, a logo, arrows, price flashes or a frame. Draw these on their own layers in Vectornation so they stay sharp at any size and stay editable.
If you need part of the picture as vectors, image trace can turn an image into shapes. Vectornation's trace keeps sharp corners sharp and makes circles and lines exact, which suits logos and simple graphics far better than photographs.
Vectornation places many other picture formats too: PNG, JPEG, GIF, BMP, WebP, TIFF, ICO, Targa, PCX, HEIC, JPEG XR, JPEG 2000 and PICT, so the PSD is one source among many.
Sending it back
File > Export > PSD writes a layered file, which means the person who sent you the original can open your version and still pick layers apart. That keeps the job editable at both ends rather than handing over a flat picture.
If the next stop is a printer rather than a Photoshop user, a PDF is usually the better choice. Vectornation exports PDF with bleed and printer's marks, and PDF/X-4 in CMYK when a printer asks for it, keeping the vector parts as vectors.
Tips for files from Photoshop users
Ask for the PSD at the size it will be used. A small web image cannot become a sharp poster however it is opened.
Check the colour mode. Photographs prepared for screens are usually in RGB. If the job is going to print, use View > Colour proofing to soft-proof with the printer's CMYK profile and see how the photograph will shift before you commit.
Name your layers. Files from other people arrive with names like Layer 37. A minute spent renaming them saves confusion when you send the file back.
Vectornation by Zaweba is free software for Windows, works offline and needs no account.