JxBrowser is using Chromium, including some libraries under LGPL.
Take a look at the list of Chromium components and their associated licences used in JxBrowser.
See the text of LGPL 2.1 and 2.0.
LGPL allows to distribute the work using LGPL component under the terms
of the author’s choice, provided that:
LGPL License ∙ Section 6a) Accompany the work with the complete corresponding machine-readable source code for the Library including whatever changes were used in the work (which must be distributed under Sections 1 and 2 above [...]
c) Accompany the work with a written offer, valid for at least three years, to give the same user the materials specified in Subsection 6a, above, for a charge no more than the cost of performing this distribution.
d) If distribution of the work is made by offering access to copy from a designated place, offer equivalent access to copy the above specified materials from the same place.
The source code of LGPL library is located in the archive with JxBrowser object files and the build script in jxbrowser-7.28-relink.zip
LGPL License ∙ Section 6a) [...] and, if the work is an executable linked with the Library, with the complete machine-readable “work that uses the Library”, as object code and/or source code, so that the user can modify the Library and then relink to produce a modified executable containing the modified Library. (It is understood that the user who changes the contents of definitions files in the Library will not necessarily be able to recompile the application to use the modified definitions.)
It is possible to download JxBrowser in a form of object files, that allow to relink it with a modified version of LGPL components: jxbrowser-7.28-relink.zip
LGPL License ∙ Section 6[...] you may also combine or link a “work that uses the Library” with the Library [...], provided that the terms permit modification of the work for the customer’s own use and reverse engineering for debugging such modifications.
See the license agreement, quoting:
5.1. General License Restrictions. You may NOT: a) modify, adapt, alter, translate, decompile, reverse engineer, or disassemble the Software, except as may be required to replace a third party Open Source Component that is used in the Software.
LGPL License ∙ Section 6You must supply a copy of this License.
The license text files are provided in the download archive, available on the product page.
LGPL License ∙ Section 6You must give prominent notice with each copy of the work that the Library is used in it and that the Library and its use are covered by this License.
See the notice in Licensing and Pricing