Exhibit 10.23

                                   GUARANTY

    THIS GUARANTY dated as of December 24, 1997 (the "Guaranty"), made by 
GENIE INTERACTIVE, INC., a New Jersey corporation, with an address at 294 
State Street, Hackensack, New Jersey 07601, IDT AMERICA, CORP., a New Jersey 
corporation, with an address at 294 State Street, Hackensack, New Jersey 
07601, IDT INTERNATIONAL, CORP., a New Jersey corporation, with an address at 
294 State Street, Hackensack, New Jersey 07601, IDT INTERNET SERVICES, INC., 
a Delaware corporation, with an address at 294 State Street, Hackensack, New 
Jersey 07601, INTERNET ONLINE SERVICES, INC., a New Jersey corporation, with 
an address at 294 State Street, Hackensack, New Jersey 07601, MEDIA RESPONSE, 
INC., a New Jersey corporation, with an address at 294 State Street, 
Hackensack, New Jersey 07601, NEW WORLD TELECOMMUNICATIONS, CORP., a New 
Jersey corporation, with an address at 294 State Street, Hackensack, New 
Jersey 07601, and YOVELLE RENAISSANCE CORPORATION, a Delaware corporation, 
with an address at 294 State Street, Hackensack, New Jersey 07601 (jointly 
and severally, the "Guarantor"), in favor of TRANSAMERICA BUSINESS CREDIT 
CORPORATION, a Delaware corporation, ("TBCC") having its principal office at 
9399 West Higgins Road, Suite 600, Rosemont, Illinois 60018 and having an 
office at 16133 Ventura Blvd., Suite 700, Encino, California 91436, with 
respect to the "Indebtedness" (as defined below) of IDT CORPORATION, a 
Delaware corporation (the "Borrower").

    1.  Guaranty.  The Guarantor hereby (a) unconditionally and irrevocably 
guarantees the punctual payment and performance when due (whether at stated 
maturity, by acceleration or otherwise) of all of the Indebtedness, and (b) 
agrees to pay any and all reasonable costs and expenses (including reasonable 
attorneys' fees and related expenses) incurred by the TBCC in enforcing any 
rights under this Guaranty. As used herein, "Indebtedness" means and includes 
all loans (including the Loans), advances, debts, liabilities, obligations, 
covenants and duties owing by Borrower to TBCC of any kind or nature, present 
or future, whether or not evidenced by any note, guaranty or other 
instrument, which may arise under, out of, or in connection with, any present 
or future Loan and Security Agreement between Borrower and TBCC (the "Loan 
Agreement"), any other Loan Document or any other agreement executed in 
connection herewith or therewith, whether or not for the payment of money, 
whether arising by reason of an extension of credit, opening, guaranteeing or 
confirming of a letter of credit, loan, guaranty, indemnification or in any 
other manner, whether direct or indirect (including those acquired by 
assignment, purchase, discount or otherwise), whether absolute or contingent, 
due or to become due, now due or hereafter arising and however acquired. The 
term "Indebtedness" includes, without limitation, all interest (including 
interest accruing on or after an Insolvency Event, whether or not an allowed 
claim), charges, expenses, commitment, facility, closing and collateral 
management fees, letter of credit fees, reasonable attorneys' fees, and any 
other sum properly chargeable to Borrower under the Loan Agreement, the other 
Loan Documents or any other agreement executed in connection herewith 
or therewith. (Capitalized terms used in this Guaranty, which are not defined, 
shall have the meanings set forth in the Loan Agreement.)

    2.  Guaranty Absolute.  The Guarantor guarantees that the Indebtedness 
will be paid and performed strictly in accordance with the terms of the Loan 
Agreement regardless of any law, regulation or order now or hereafter in 
effect in any jurisdiction affecting any of the terms or the rights of the 
TBCC with respect thereto. The liability of the Guarantor under this Guaranty
shall be absolute and unconditional irrespective of:

         (a) any lack of validity or enforceability of the Loan Agreement or 
any other agreement or instrument relating thereto, including, without 
limitation, this Guaranty (collectively, the "Loan Documents");


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         (b) any change in the time, manner or place of payment of, or in any 
other term of, all or any of the Indebtedness, or any amendment or waiver of 
any term of or any consent to departure from the Loan Agreement or any other 
Loan Document;

         (c) any exchange, release or non-perfection of any collateral, or any
release, amendment or waiver of any term of, or consent to departure from, 
any other guaranty for all or any of the Indebtedness;

         (d) any failure on the part of the TBCC or any other person or 
entity to exercise, or any delay in exercising, any right under the Loan 
Agreement or any other Loan Document; or

         (e) any other circumstance which might otherwise constitute a 
defense available to, or a discharge of, the Borrower, the Guarantor or any 
other guarantor with respect to the Indebtedness (including, without 
limitation, all defenses based on suretyship or impairment of collateral, and 
all defenses that the Borrower may assert to the repayment of the 
Indebtedness, including, without limitation, failure of consideration, breach 
of warranty, fraud, payment, statute of frauds, bankruptcy, lack of legal 
capacity, statute of limitations, lender liability, accord and satisfaction, 
and usury) or which might otherwise constitute a defense to this Guaranty and 
the obligations of the Guarantor under this Guaranty.

The Guarantor hereby agrees that if the Borrower or any other guarantor of all 
or a portion of the Indebtedness is the subject of a bankruptcy proceeding 
under Title 11 of the United States Code, it will not assert the pendency of 
such proceeding or any order entered therein as a defense to the timely 
payment of the Indebtedness. This Guaranty shall continue to be effective or 
be reinstated, as the case may be, if at any time any payment of any of the 
Indebtedness is rescinded or must otherwise be returned by the TBCC upon the 
insolvency, bankruptcy or reorganization of the Borrower or otherwise, all as 
though the payment had not been made.

    3. Waiver. The Guarantor hereby waives promptness, diligence, notice of 
acceptance and any other notice with respect to any of the Indebtedness and 
this Guaranty and any requirement that the TBCC protect, secure, perfect or 
insure any security interest or lien or any property subject thereto or 
exhaust any right to take any action against the Borrower or any other person 
or any collateral.

    4. Subrogation. The Guarantor hereby irrevocably waives, to the fullest 
extent permitted by law, any and all claims, rights or remedies which it may 
now have or hereafter acquire against the Borrower that arise hereunder or 
from the performance by him hereunder including, without limitation, any 
claims, rights or remedies of subrogation, reimbursement, exoneration, 
contribution, indemnification or participation in any claims, rights or 
remedies of the TBCC against the Borrower or in any security which the TBCC 
now has or hereafter acquires, whether or not the claims, rights or remedies 
arise in equity, under contract, by statute, under common law or otherwise.

    5. Representations and Warranties. The Guarantor hereby represents and 
warrants as follows:

         (a) Power and Authority. The Guarantor has full power, authority, 
capacity and legal right to execute and deliver and to perform its 
obligations under this Guaranty and the other Loan Documents to which the 
Guarantor is a party.

         (b) Enforceability. This Guaranty and the other Loan Documents to 
which the Guarantor is a party have been duly executed and delivered by the 
Guarantor and constitute a legal, valid and binding obligation of the 
Guarantor, enforceable against the Guarantor, its


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successors and assigns (and, in the case of Guarantors who are individuals, 
their heirs, estate, personal representatives, executors and administrators) 
in accordance with their respective terms, except as enforceability may be 
limited by applicable bankruptcy, insolvency, reorganization, moratorium or 
similar laws affecting the enforcement of creditors' rights generally.

         (c)  No Conflicts. The execution, delivery and performance of this 
Guaranty and the other Loan Documents to which the Guarantor is a party will 
not violate any requirement of law or contractual obligation of the Guarantor 
or result in the creation or imposition of any lien on any of the property or 
assets of the Guarantor, except for liens (if any) granted in favor of the 
TBCC pursuant to the Loan Documents.

         (d)  No Consents. No consent of any other Person and no consent, 
license, permit, approval or authorization, of, exemption by, notice or 
report to, or registration, filing or declaration with, and governmental 
authority is required in connection with the execution, delivery, 
performance, validity or enforceability of this Guaranty and the other Loan 
Documents to which the Guarantor is a party.

         (e)  Solvency. The fair value of the property of the Guarantor 
exceeds the total amount of liabilities (including, without limitation, 
contingent liabilities) of the Guarantor; the present fair saleable value of 
the assets of the Guarantor exceeds the amount that will be required to pay 
the probable liability of the Guarantor on its existing debts as they become 
absolute and matured; the Guarantor is able to realize upon its assets and 
pay its debts and other liabilities, contingent obligations and other 
commitments as they mature and the Guarantor does not intend to, and does not 
believe that it will, incur debts or liabilities beyond the Guarantor's 
ability to pay as the debts and liabilities mature. In computing the amount 
of contingent liabilities at any time, it is intended that the liabilities 
will be computed at the amount which, in light of all facts and circumstances 
existing at such time, represents the amount that can reasonably be expected 
to become an actual or mature liability.

         (f)  Absence of Litigation. Except as otherwise heretofore disclosed 
to the TBCC in writing, there are no actions, suits, investigations, 
litigation or proceedings pending or, to the knowledge of the Guarantor, 
threatened against or affecting the Guarantor or any of its properties before 
any court, arbitrator or governmental department, commission, board, bureau, 
agency or instrumentality, domestic or foreign, that has an amount in 
controversy in excess of $25,000, or which purports to affect any part of the 
transactions contemplated hereby or by the other Loan Documents to which the 
Guarantor is a party or the legality, validity or enforceability of this 
Guaranty or other other Loan Documents to which the Guarantor is a party.

         (g)  Financial Condition. The financial condition and net worth of 
the Guarantor contained in the financial statements, dated _______________ 
are true and correct; there is no event, fact, circumstance or condition 
known to the Guarantor which is inconsistent with the statements or is 
required to be disclosed in order to cause the statements not to be 
misleading; and the Guarantor knows of no reason why it will not be able to 
perform duly and promptly its obligations under this Guaranty.

         (h)  Payment of Taxes. The Guarantor has filed all tax returns 
(federal, state, local and foreign) required to be filed and paid all taxes 
shown thereon to be due, including interest and penalties, except for such 
taxes as are being contested in good faith and by proper proceedings.

    6. Covenants. The Guarantor covenants and agrees that, so long as any 
part of the Indebtedness shall remain unpaid, the Guarantor shall provide the 
TBCC with financial statements relating to the financial condition and net 
worth of the Guarantor and the ability of the Guarantor to satisfy its 
obligations hereunder, such financial statements to be certified as being


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true and correct by the Guarantor. Such financial statements shall be 
provided (i) in the case of a Guarantor who is an individual, as of December 
31 of each year, by January 31 of the following year; (ii) in the case of a 
Guarantor which is a corporation, partnership, limited liability company, 
trust, or any other entity or organization, within 120 days after the end of 
the Guarantor's fiscal year.

     7. Amendments, Etc.  No amendment or waiver of any provision of this 
Guaranty or consent to any departure by the Guarantor therefrom shall in any 
event be effective unless the same shall be in writing and signed by the 
TBCC, and then such waiver or consent shall be effective only in the specific 
instance and for the specific purpose for which given.

     8. Addresses for Notices.  All notices and other communications provided 
for hereunder shall be in writing (including by telecopier) and, if to the 
Guarantor, mailed or delivered to him at its address specified on the first 
page of this Guaranty, if to the TBCC, mailed or delivered to it at the 
address of the TBCC specified on the first page of this Guaranty, or as to 
each party at such other address as shall be designated by the party in a 
written notice to the other party. All the notices and other communications 
shall, if mailed, be effective when deposited in the mail addressed as 
aforesaid.

     9. No Waiver; Remedies.  No failure on the part of the TBCC to exercise, 
and no delay in exercising, any right hereunder shall operate as a waiver 
thereof. No single or partial exercise of any right hereunder shall preclude 
any other or further exercise thereof or the exercise of any other right. The 
remedies herein provided are cumulative and not exclusive of any remedies 
provided by law.

     10. Right of Set-off.  The TBCC is hereby authorized at any time and from 
time-to-time following an Event of Default, to the fullest extent permitted 
by law,, to set off and apply any and all deposits (general or special, time 
or demand, provisional of final) at any time held and other indebtedness at 
any time owing by the TBCC to or for the credit or the account of the 
Guarantor against any and all of the obligations of the Guarantor now or 
hereafter existing under this Guaranty, irrespective of whether or not the 
TBCC shall have made any demand under this Guaranty and although such 
obligations may be contingent and unmatured. The TBCC agrees promptly to 
notify the Guarantor after any such set-off and application, provided that 
the failure to give such notice shall not affect the validity of such set-off 
and application. The rights of the TBCC under this Section are in addition to 
the other rights and remedies (including, without limitation, other rights of 
set-off) which the TBCC may have.

     11. Continuing Guaranty; Assignments.  This Guaranty is a continuing 
guaranty and shall (a) remain in full force and effect until the indefeasible 
payment in full of the Indebtedness and all other amounts payable under this 
Guaranty, (b) be binding upon the Guarantor and its successors, assigns, 
beneficiaries and indorsees (including, without limitation, the heirs, 
administrators, executors and estate of the Guarantor), except that no 
Guarantor shall assign or transfer any of its rights or obligations hereunder 
without the prior written consent of the TBCC, and (c) insure to the benefit 
of the be enforceable by the TBCC and its successors, transferees and 
assigns. Without limiting the generality of the foregoing clause (c), the 
TBCC may assign or otherwise transfer any of the Indebtedness to any other 
person or entity, and such other person or entity shall thereupon become 
vested with all the rights in respect thereof granted to the TBCC herein or 
otherwise. This Guaranty and the obligations of the Guarantor hereunder shall 
terminate upon the indefeasible payment in full of all of the Indebtedness 
and all other amounts payable under this Guaranty.

     12. Subordination.  Any and all payments on any indebtedness or 
obligations of the Borrower now or hereafter owing to the Guarantor other 
than in respect of salaries or wages (the "Junior Debt") is hereby 
subordinated and junior in right of payment and exercise of remedies to


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the prior payment in full in cash of the Indebtedness. Upon the written 
request of the TBCC, the Junior Debt shall be collected, enforced and 
received by the Guarantor as trustee for the TBCC and paid over to the TBCC 
on account of the Indebtedness but without reducing or affecting in any 
manner the liability of the Guarantor under the other provisions of this 
Guaranty.

    13. GOVERNING LAW. THIS GUARANTY SHALL BE GOVERNED BY AND CONSTRUED IN 
ACCORDANCE WITH THE INTERNAL SUBSTANTIVE LAWS OF THE STATE OF ILLINOIS 
WITHOUT GIVEN EFFECT TO CONFLICTS OF LAW PRINCIPLES THEREOF.

    14. Telecopier; Counterparts. This Guaranty may be executed and delivered 
by telecopier or other facsimile transmission with the same force and effect 
as if the same was a fully executed and delivered original counterpart. This 
Guaranty may be executed by the parties in one or more counterparts, each of 
which shall be an original and all of this shall constitute one and the same 
agreement.

    15. CONSENT TO JURISDICTION.

        (a)  THE GUARANTOR HEREBY IRREVOCABLY SUBMITS TO THE JURISDICTION OF 
ANY ILLINOIS STATE OR FEDERAL COURT SITTING IN ILLINOIS IN ANY ACTION OR 
PROCEEDING ARISING OUT OF OR RELATING TO THIS GUARANTY OR ANY OTHER LOAN 
DOCUMENTS, AND THE GUARANTOR HEREBY IRREVOCABLY AGREES THAT ALL CLAIMS IN 
RESPECT OF THE ACTION OR PROCEEDING MAY BE HEARD AND DETERMINED IN SUCH 
ILLINOIS STATE OR FEDERAL COURT. THE GUARANTOR HEREBY IRREVOCABLY WAIVES, TO 
THE FULLEST EXTENT HE MAY EFFECTIVELY DO SO, ANY OBJECTION TO THE LAYING OF 
VENUE OR ANY DEFENSE OF AN INCONVENIENT FORUM WHICH HE MAY NOW OR HEREAFTER 
HAVE TO THE BRINGING OF SUCH ACTION OR PROCEEDING. THE GUARANTOR IRREVOCABLY 
CONSENTS TO THE SERVICE OF ANY AND ALL PROCESS IN ANY SUCH ACTION OR 
PROCEEDING BY THE MAILING OF COPIES OF SUCH PROCESS TO THE GUARANTOR AT HIS 
ADDRESS SPECIFIED ON THE FIRST PAGE OF THIS GUARANTY. THE GUARANTOR AGREES 
THAT A FINAL JUDGMENT IN ANY SUCH ACTION OR PROCEEDING SHALL BE CONCLUSIVE 
AND MAY BE ENFORCED IN OTHER JURISDICTIONS BY SUIT ON THE JUDGMENT OR IN ANY 
OTHER MANNER PROVIDED BY  LAW.

        (b)  NOTHING IN THIS SECTION SHALL AFFECT THE RIGHT OF THE TBCC TO 
SERVE LEGAL PROCESS IN ANY OTHER MANNER PERMITTED BY LAW OR AFFECT THE RIGHT 
OF THE TBCC TO BRING ANY ACTION OR PROCEEDING AGAINST THE GUARANTOR OR HIS 
PROPERTY IN THE COURTS OF ANY OTHER JURISDICTIONS.

    16. JURY TRIAL WAIVER. THE GUARANTOR AND, BY ITS ACCEPTANCE HEREOF, THE 
TBCC, HEREBY WAIVE ANY RIGHT TO TRIAL BY JURY IN ANY ACTION OR PROCEEDING IN 
ANY COURT RELATING TO, IN CONNECTION


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WITH OR ARISING UNDER THIS GUARANTY OR ANY OF THE OTHER LOAN DOCUMENTS.

     IN WITNESS WHEREOF, the Guarantor has executed this Guaranty as of the 
date first above written.


GENIE INTERACTIVE, INC.                INTERNET ONLINE SERVICES, INC.

By /s/ Stephen Brown                   By /s/ Stephen Brown
   -----------------                      -----------------
Title Chief Financial Officer          Title Chief Financial Officer


IDT AMERICA, CORP.                     MEDIA RESPONSE, INC.

By /s/ Stephen Brown                   By /s/ Stephen Brown
   -----------------                      -----------------
Title Chief Financial Officer          Title Chief Financial Officer


IDT INTERNATIONAL, CORP.               NEW WORLD
                                       TELECOMMUNICATIONS, CORP.

By /s/ Stephen Brown                   By /s/ Stephen Brown
   -----------------                      -----------------
Title Chief Financial Officer          Title Chief Financial Officer

IDT INTERNET SERVICES, INC.            YOVELLE RENAISSANCE
                                       CORPORATION

By /s/ Stephen Brown                   By /s/ Stephen Brown
   -----------------                      -----------------
Title Chief Financial Officer          Title Chief Financial Officer


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